That's all I've ever done for 40 years was just use the caliper pad gap, though I've never removed a tire to do it just let the air out so you don't poke a tube with a spoke end. The one thing you do is you close the caliper down so it's just barely missing the rim equally on both sides.

Here's more detail on this: http://www.kenkifer.com/bikepages/skills/spokes.htm
And here's a video: http://www.graspr.com/videos/Bicycle...ntenance-Video

By the way, you don't want to just tighten because you could over tighten, they should be snug. If you finding that you "need" to over tighten then actually you need to loosen the opposing spoke instead. But read and listen to the video carefully there are important tips that you could miss.