Pre-empts are difficult to accurately defend against because they prevent your opponents from having a conversation.
Therefore my tip is to pre-empt as high as possible. If you are non-vulnerable against vulnerable opponents and you play weak twos consider opening at the three-level with only a good six-card suit. This works really well when your suit is spades.
At the same vulnerability consider opening 4C/D rather than 3C/D. Remember this “THEY CAN’T SEE YOUR HAND”