I have always tried to go for a style/ themed army. So when I did Eldar, it was basically bikes, spiders,spears, vypers.
I rarely ran vehicles with my tau, maybe played a devil fish once.
I sold most of my stuff, and when I got back, I started with SW, and have tried to make my force fluffy, so death wolves etc. the painting guide had lots of fluff to read.
I always wanted ad mech, so now I am focusing on that. I will do with them what I did with old tau, and focus on trying to run them with fluff type tactics, instead of what is powerful. This makes the game so much more fun, and requires me to fight more tactically.
I like foot slogging, or mech infantry, but to,run them that way, using other vehicles to support them. I guess it must be from when I studied US army FM 7-7
I like playing a fluff army, after reading a few 40k books, I like my force to operate like the stories, might not be competitive, but sure is fun. If I play against a cheese list, that is ok, I like the challenge.