I did both, myself. Following the instructions, you could build really cool things you couldn't design yourself with a 10 year old brain. Not following the instructions, you got to endeavor in trial and error, and critical thinking, etc. Both had their merits.
Same here. I had another Lego enthusiast friend as a kid. Every time one of us got a new set we would do it individually then either trade sets or just let the other borrow it to do the same. Then it got thrown into the GIANT bucket of old Legos we used for our creative projects which we would work on together.
A couple of our creative projects were even put on display at some local libraries. That was a really satisfying experience as an 8-12 year old.
