I don't get how raising 3x BB is transparent. If you raise 3x BB every time you raise preflop when its folded to you, how is anyone going to know if you're stealing or not?

When the blinds are low and I'm opening with a raise, I do 3 or 4x BB, on steals, AA, KK, QQ, JTs, 66, etc., and when the blinds are big I typically do 2.5x BB on every hand. Occasionally I'll mix it up a bit, but not on any specific hand.

There's nothing transparent about it, and that's really the entire point. You don't want them to know when they should reraise, call, or fold. Reraise my 3xBB bet all in once and I may fold. Do it again and I may have AA this time and I take your stack.

Where I do change my raising amount is if people have limped in or raised in front or me or anything like that. Then I'll consider adjusting my raise based on the situation (how to get the most money in the pot, isolating the preflop raiser, possibly folding everyone out, etc.).