Just look for double bars. If you see double bars you know it'll be fat sune/antisune. If no double bars learn to recognize which ways the bars point if it's only a single bar for the other two small bolt shapes. There are the large bolt shapes that are kind of like a Z, only two of those, and the way I recognize those is put the bars pointing to the right, I'll then know if it's R' F or R B'. I know to move the bars to the opposite side (so if the bar is at BU slot then do R' F etc and if it's at FU slot do R B' etc).
Most OLLs have easy recognition like this. Such as the sune/antisune that turns it into a T shape (has headlights with two dots, you put it so one dot is on R and then you either have front headlights or back headlights, you move R toward the headlights and finish out the alg). Etc.
The bolt pattern that gives me the most problem is OLL 12 (F RUR'U' F' U F RUR'U' F'). I get that somewhat mixed up with the other one with just a single bar quite a bit and have to AUF a few times to get it right. Although the "fat" version of OLL 10 (y' R U R' U R' F R F' R U2 R'). That's the 3rd alg listed but I like redundancy because it makes it easier to learn OLLs (with the given similarities).
Another trick: With the dot cases like OLL 3 and 4, if doing OLL 4 is awkward because of the U instead of the U', then you can do f R U R' U' f' U' f U R U' R' f' instead (it's the T shape backwards as if the T is on the left instead of right. Meaning if you see the T on the left you can do f' U R U' R' f' instead of U2 F R U R' U' F'). You can do that same trick as the T with the B shapes with the straight line (OLL 43 and 44).
Learning the inverse of cases makes things easier. Such as the H shape and Manta shape can be solved using the F/f sexy move F'/f' (F SM' F' f SM f' and f SM' f' F SM F'). You can also do neat things with F/f SM F/f' AUF F/f SM/SM' F'/f/.