Avoiding tension

I have never bothered with checking my tension before knitting anything, which is probably why a lot of the jumpers I have made have been on the roomy side (which I like anyway), but I’m about to break with tradition and knit a tension square for my next project, a doll outfit in 3 ply from a vintage pattern, as I really want it to sit properly.

Do y’all check your tension before knitting from a pattern? And if so, do you keep your squares and what do you make with them?