Hello Hopey,
Usually, the stronger your range, the bigger you can open, which is why you see some people suggest bigger from EP and smaller from BU and why articles suggest 4x (SHC gives very tight ranges).
3x will usually be OK from any position. However, if you open as wide as you should on BU, 3x might be too big and 2-2.5x will be better.
That said, having dynamic open raise sizing is best. If you know your table and you know exactly what you want to acheive, play exploitable to what gets you max. At a table full of call happy fish I would raise bigger with strong hands in any position without giving it a second thought! Worry about people adjusting and getting a read on you when they do, not even before you do that certain obvious thing because chances are they do not adjust at all, whatever you do.
Another situation would be in BU when you have tight blinds, open often and small. They will fold anyway, when they don't you only play the nuts. If blinds are fish who like to call, open a bit tighter with hands that play well postflop and open bigger to get as much money in as possible vs fish, having a stronger range and position vs him.
Hope it helps!
Cheers.