What I should have done with a material advantage

It's common in games at my current level for one side to realize an early significant material advantage, even advantage of a piece (usually through a blunder rather than by good play).  Until now, my immediate strategy when realizing such an advantage has been: (a) make sure my pieces and king are safe, then (b) try to force a trade of pieces. The idea is that as long as I keep my king and pieces safe, an extra piece in the end will at least overwhelm my opponent's pawns and, if necessary, lead mine to promotion. I suppose this strategy would typically help me win (assuming I'm using all of my pieces), but I don't think it helps me learn to play better chess. In particular, as long as my king and pieces are safe, I should be using my extra material more actively and with greater coordination.

Re-reading Dan Heisman's "When You're Winning, It's a Whole Different Game" and "Trading Pawns When Ahead" (A Guide to Chess Improvement), it's clear I've been applying several less accurate or, even, wrong principles. 

When Winning...

As DH makes clear, "Think defense first!" does not mean "Play passively" (let alone "Play paranoid"). Rather, the principle is about order of priority: "Attack all you want, but first make sure your opponent cannot get back in the game via a tactic" (p. 283). For the reasons I mentioned earlier, it is often advantageous to trade pieces when ahead in material--but not when other moves would be more advantageous. And as long as your own material is safe, you should use all of your pieces all of the time; otherwise, you're not really playing with an advantage.

Here is a game from last Tuesday using the wrong "principles."