I usually shoot 2-3X/week, when my kids are in school for about an hour or so, at the local ranges I'm a member of.
I bring along either the AR (ArmaLite M15A2) or a bolt-action (usually 8mm Yugo M24/47 Mauser or Long Lee-Enfield [CLLE]), but I also always bring along a pistol (9X18 Makarov). I find lately the pistol is the one I practice with the most, usually about 35-50 rounds each session. Maks are a lot of fun, and the ammo's cheap.
The bolt actions I'll shoot about 20-30 milsurp rounds, max. The AR- well, I could shoot it all day, but replacing that huge pile of brass is getting harder (and more expensive) to do....time to get a .22 LR kit for it, I think.
So, two guns at a time at the range, and I'll try and clean them as best as I can when I'm there, since it's usually deserted during the day, and I disturb nobody with it. Otherwise I clean the guns in the afternoon when the kids come home, so I can watch them while they are playing outside, AND become habituated to seeing guns all the time, so they don't have to swallow all the anti-gun fear programming they hear at school.
Anyway, as the man said, frequency is the key. I don't have years of muscle memory in my body for shooting- I got a late re-start on shooting as an adult, so I have to keep it up, or else I get lots of flyers :^). Even 10 shots with each gun in a session might be worth it, because, esp. lately, I try to make each shot count.
I don't own any shotguns (yet), but once in a while I'll take out the flintlocks and blast away with them- always fun, and a challenge (Esp. with the Brown Bess).