How do I make better purl stitches?

I typically knit with just the right amount of tension, according to my guru, who is now 800 miles away. Every time I knit something that has a few rows of ribbing, it always turns out floppier and bigger than expected. I know all about gauge, but I’m one of those terribly stubborn people who hates doing the swatches first. I prefer to barrel on in and see what I end up with. Any suggestions from the knitters out there on how to tighten up those obnoxious purls as I’m working?