i focus train most players unless they there are a few skills close to the max, then i try to train all to get them all up inside a few weeks.

For fitness I don't focus unless there is a player at a cap, then I would. I think the focus on works best when you are ready to take your players beyond a base situation. I am building my players to have a strong fitness base this season so it doesn't cost me a ton of cash to start next season. Next season I will begin to be more deliberate in focusing on attacking skills, but I will only be in Div 4 next year, so I may still do quite a bit of fitness skills.