I use warmups sets. If you really want to see how important warmups are try this:
One week when you're benching throw a weight on the bar that you think you can do sets of 8 with (or whatever weight you would usually use). do your workout with that weight. then next week when you bench again use the same weight but this time do a few warmup sets beforehand. see how your performance compares and how you feel during/after the set.