Very very *very* simple, fast, & easy technique: hold the Ctrl key down and stretch the clip out longer on the timeline. The farther you stretch it, the slower it will play.
Three ways:
1. CTRL+Drag right edge of clip/event
2. Right click event, choose Envelopes/Velocity envelope, set to any value less than 100% and greater than 0%
3. Right click event/clip, choose Properties, then in Playback rate, set to any value less than 1.00.