I pluck/thump against the 24th fret on the tobias. I pluck/thump between the p/u's on the fretless carvin.
For fingerstyle, I normally play on top of the bridge p'u. When it's time to get some gritty attack, I'm on top of the neck p/u. But I'll change it up, depending on what sounds better.
When tapping, I keep a relationship of left hand position and right hand tapping. I.E. : fret on 12th fret, tap 20th or so. If the left hand goes to say 15th fret, tap at about 22nd. But I mix it up so dang much I can't explain it perfectly. But keeping that ratio between your hands helps bring about different tones and inflections. Give it a try.