I use two tools:
1) A Tweeten Metal Tip Trimmer (to shape the cue tip). Note - Use 120 grit sandpaper only. It works just as well as the 60 grit (that comes with the Trimmer) and makes it easy to control the trimmer until the tip is the right shape.
When using this tool, I hold the shaft in my left hand, near the tip, and rotate the cue a few degrees while using one left and right stroke with my right hand. I then rotate the cue a little more, then give the tip a left and right stroke with the Trimmer. In less than a minute, you'll have a properly shaped tip.
2) A Cuetec Bowtie to roughen the tip once it's been properly shaped.
Using these two tools will help maintain chalk retention and provide a good feel.
Note: I like Triumph (standard) medium tips. They're a little hard, but are easy to shape and last a long time.