I usually count the longest carbon chain first to get the basis of the structure (e.g pentane) and then name the structure around that.
- look for methyl, ethyl groups
-look for carboxylic acid groups
Then i put the name of the structure together
You just need to think logically and also there is the fact that you only know very few functional groups (alkene, alkane, aldehyde, ketone, ester, carboxylic acid) that you learn at a level, so the structure is actually never too complicated.
I just want to stress that you practise and google skeletal formula practise questions on google. You'll never get better unless you practise and maybe get quite a few questions wrong but eventually you'll get them all right.