What you don't want to do, regardless of whatever strategy you decide to employ, is get in a bidding war. The only person who wins in a bidding war is the seller. Figure out what the item is worth to you and don't bid more than that.
In figuring out what the item is worth, do some diligence. Use the "advance" search option to see what similar items have gone for, so that you have an idea of it's market value. Ask the seller for better pictures if you aren't satisfied with what has been posted. Know what you are bidding on.
Occasionally you will get a steal deal, but generally results will fall within a traditional range for that item, regardless of strategy. That's been pretty consistent, regardless of bid pattern and history, over the auctions I've followed, about 35,000 over the past 10 years.
The one key to not being roadkill, is to not overbid, and you need to know what the market value is to avoid doing that. If you lose it's no big deal. There are always more opportunities.