Having some direction in your play session is useful. Identifying ur weakness and strengths, what skillsets do you want to focus on. Can i play more efficiently, am I hitting the keys to hard, to lightly, is there too much tension in my wrist/fingers/forearm/etc, do I encounter problems on speed maps, does my stamina die too early on long maps, am i struggling to hit LN on time, etc. If you want to focus on stamina, then how would you do that. You put more time into stamina maps. If its LN that needs work, then do more LN. If Acc is an issue, spending a few days consistently gettin good acc on easier stuff generally does the job well.
Basically, have some direction in your play session and something to improve and work towards.