Ah, this was a big portion of my thesis. I can discuss how the British recruited in the 18th century.

Let me start of with the statement that most soldiers in the 18th century British army volunteered to join the army, with very few conscripts in proportion. The navy had more impressed sailors than the army would with soldiers. General Dalrymple noted that volunteer soldiers made better soldiers than conscripted ones and said:

The first and most eligible by volunteers, the last and worst by a press. By the first method, numbers of good men are enrolled, but the army is greatly obliged to levity, accident, and the dexterity of recruiting officers for them; by the second plan, the country gets clear of their banditti, and the ranks are filled up with the scum of every county, the refuse of mankind. They are marched loaded with vice, villainy, and chains, to their destined corp, where, when they arrive, they corrupt all they approach, and are whipy out, or desert in a month.

Sometimes criminals had the choice given by the judge to either spend time in prison or service in the army. Most recruiters and military leaders did not want criminals in their regiments, and often they sent the battalions of criminal soldiers to more remote places such as the West Indies or Africa. Doing this deterred men from deserting easily in such a faraway location and not corrupt other regiments as well. The army would rely more on volunteers than impressed soldiers or criminals serving their sentences in the army. Between 1775-1781 only 764 convicted criminals received a royal pardon and choice of enlistment instead of prison

During the 18th century Britain had pushed a few Press Acts onto the population in order to gain more soldiers. The Press Acts only lasted a short while for each one: 1703-1711, 1743-44, 1756-57, 1778-79, 1783. Of course they only occurred during war time and often at the time of desperation for soldiers. The 1778 Press act resulted from the joining of France and Spain in the American War of Independence, with the war expanding to the islands in the Caribbean, and Gibraltar. In comparison, the 1778 Press Act acquired just over a thousand men while over twenty thousand soldiers volunteered for service. While the Act became unpopular and ceased by 1779, it did push for those that could enlist to do so instead of being impressed into service. The navy continued impressments throughout the century. Press acts targeted men either with ungainful employment or the idle, but very few criminals. Itinerant workers could be farmers in between seasons looking for extra work after the harvest season.

The recruiting party would be the most common way of recruitment in the 18th century. The party consisted of an officer, a sergeant, a drummer (or piper if it's a Highland regiment), and several enlisted men. They roved around a region to pull recruits, going to taverns, market days, and fairs since a lot of traffic went to those places. Either in peacetime or in war, recruiting parties would attempt to get recruits for regiments that needed additional men or to replace those lost in battles. Many regiments reduced their strengths in peacetime to just a few hundred men instead of a full battalion - which could be 500 or 1000 depending on the years - since the army did not need to pay for that many men to just stand around. When war came close to starting, the recruiters would then get soldiers to put the regiment back to full strength. During the American War of Independence, the regiments would leave an "additional company" back in Britain to act as the recruiting party.

Did recruits enlist out of patriotic duty and spiritual martialism? Maybe. But recruiting parties used money to gain enlisted men. The sergeants and officers offered bounties for those that joined, usually a few pounds in addition to the "King's Shilling", as means of enticement. They promised wages that competed again the rates of an unskilled laborer, but did not tell them about the stoppages in a soldier's pay. Stoppages included the payment of rations, uniforms, accoutrements, etc. Sometimes Parliament allowed for the increased allowance in bounties to entice more recruits. Not all recruiting parties worked the same way. Some used more honest methods and some used trickery. Deceiving drunken recruits into joining by unwillingly take the King's Shilling. John Matson fell into a position of being forced into the army one night. Kidnapped and forced to swear into the 100th Regiment, he felt resentment towards the army and made every attempt to desert. Recruiting sergeants also may have bought drinks for the new recruit but covered the expenses with the recruit's new bounty money, leaving them destitute for the night and forcing them to join. John Robert Shaw had a better experience with him actually wanting to join the army at the age of 15 into the 33rd Regiment of Foot in 1776. However, some measurements of protection did exist against unwilling recruitment tactics. Recruits still had to take an Oath of Fidelity and in front of sheriff or justice. The sheriff or justice of the peace would make sure the recruit did so with the most honest intentions and not strong-armed into enlistment.

Britons also encountered promotional material such as recruiting posters and advertisements in newspapers. Literate men read the financial benefits that the military offered such as pay and pension. The promise of promotion for literate men also caught the attention of would-be recruits. The propaganda behind recruitment posters laid out the incentives for recruits to join including clothing, pay, land grants, honor, and possible pension. Financial promises encouraged recruits to join. Not only the initial enlistment bounty but some regiments offered a higher pay. The 56th Regiment of Foot offered one and a half to two guineas depending on the size of the recruit. In addition, the Royal Artillery promised a daily wage of a shilling and four pences for a recruit. The language of the recruitment posters flattered recruits into enlistment by calling them “gentlemen,” “heroes,” and stated that the recruits would serve with distinction. One poster that exists is of the 22nd Sussex Light Dragoons. The poster attempted to instill a sense of patriotism and civic duty with the nation’s need of defense against France and Spain, who had just joined the American War of Independence.

As for records, the recruiting party and regimental officers kept track of the recruits. Muster rolls described how many soldiers each company had but also who recruited them and where from. It helped with the amount of money needed for the regiment and how much more recruiting would be needed. Officers would then sign the muster rolls, especially the commandant, and then send it off. It was against the articles of war to falsify a muster roll, leading to a lot of trouble and pain if caught.

Sources:

Primary:

Matson, John. Indian Warfare, or the Extraordinary Adventures of John Watson the Kidnapped Youth, late of Kingsland Road, London; formerly of Bridlington Quay, in the County York; Architect and Builder. Written by Himself (London: Effington Wilson, 1842).

Shaw, John Robert. A Narrative of the Life & Travels of John Robert Shaw, the well digger, now resident of Lexington, Kentucky. Lexington, printed by Daniel Bradshaw, 1807.

Secondary:

Berkovich, Ilya. Motivation in War: The Experience of Common Soldiers in Old-Regime Europe. Cambridge: Cambridge University Press, 2017.

Frey, Sylvia R. The British Soldier in America: A Social History of Military Life in the Revolutionary Period. Austin: University of Texas Press, 1981

Hagist, Don. British Soldiers, American Revolution: Voices of the American Revolution. Westholme Publishing, 2012.

Way, Peter. “‘The scum of every county, the refuse of mankind’ Recruiting the British Army in the eighteenth century.” In Fighting for a Living: A Comparative Study of Military Labour 1500-2000, edited by Erik-Jan Zürcher, 291-330. Amsterdam University Press, 2013.