Not quite qualified to discuss any economic policy that may have resulted in stabilization, I can still offer a view on how some of the actions of the Julio Claudians, specifically Augustus, helped in cementing a secure frontier. The Romans primarily had 3 borders by the time of Augustus, the Britain front which is enclosed by sea, the Hanube front occupied by Germans, and then the Syrian front against Parthia. The Battle of Carrhae was lost before Caesar's time, and as a result by the time Augustus took power he engaged in dioplomacy with Parthians, which temporarily pacified that Parthian front. We know of the Roman's aggressive expansion into Germany and the Varian disaster, yet despite that Germanicus made significant push into the German territories and reclaimed the Fallen Eagle. The Britain front had a very similar occurrence, Caesar has attempted to invade Britain twice, and Claudius was able to finish it. If we go by the results of these military and diplomatic actions, we can see that it in varying degree contributed to a more secure border.

The process itself is also fairly straight forward. Romans are good at being aggressive and projecting their power, so to unstable fronts, they would invade when it's opportune, push their opponents back to clear a border for themselves, (as we see with Germanicus, who's actions, although aggressive, is performed with defensive strategy in mind), and if possible, even conquer and expand into new territories(We see this with invasion of Britain). However, against forces with similar power and organization where aggressive expansion proved difficult, they were flexible enough to appeal for peace. In other words, adapting appropriate levels of aggression for each front, but be aggressive when possible constituted the Roman's approach to borders during the early imperial days