For general target and practice handgunnery:
I maintain an inventory of many buckets each of 9mm, .38SPCL, .40S&W, and .357SIG target-velocity light reloaded rounds. And shoot frequently at the range, as indicated elsewhere on this Forum. (I also maintain an inventory of raw reloading components in these same calibers.)
For Self/Home Defense, Concealed Carry handgunnery:
I buy 50-100 rounds of a good, reliable self-defense jacketed commercial factory loads (usually the same as a local LE agency). Then shoot off a couple of magazines of these rounds to ensure that they feed properly and cycle well through the handguns. After about a year or so, I then shoot up all of the remaining SD factory rounds and start all over again. To keep the inventory fresh and also to buy and test newly developed SD ammunition.
General Practice/Policy:
High inventory of target rounds; low inventory of self-defense rounds.