Never did get around to nabbing a WASR 10 when they were "reasonable" and I still regret it...
Ive found I like functional, "military" type folding stocks the best... 4.5mm/5.5mm trunnions ( the AK74/100 series type) and the Bulgarian AR series folders ( like the SAM7sf) the best. A good folder and wood handguards is a favorite. Although Ive got more Modern options aswell.
I loath the feel of the "popsicle" type grips, and replace them with either Magpul grips, or a good quality wood one. (Z Recto on AK Files makes some of the BEST)
Magpul slings with accommodation for shooting lefty work great.
RS regulate slide mount, rear bias with an Aimpoint PRO works great with my astigmatism, and still cowitnesses well.
Really RS Regulate stuff i general is great...
A properly installed ALG is always nice, and is my preference these days. Regardless of FCG I use a good retainer plate, they make life so very much easier.
Muzzle devices depend on mounting types... if it has a 24mm threaded fsb I'll stick with either an AK74 type brake or a Flash hider to preserve the ability to mount a bayonet, and on standard style AKM type threads I HATE the slant brakes as I shoot lefty. Ive grown to like the three prong flash hiders and the Chinese type cages on those applications.
Really, thats just stuff off the top of my head. I love my AK's.... I'll likely think of more later 😆
Here is an older pic of my SAM7sf, its easly one of my overarching favorites.