[Shan]

For faster and accurate trims, especially when your zoomed in on the waveform, use the edit cursor in Slip mode. Place the edit cursor inside the clip and do the following:

Trim Clip Start to Insertion - Hit a(keyboard focus on) or Alt+Shift+7
Trim Clip End to Insertion - Hit s(keyboard focus on) or Alt+Shift+8

Use this in conjunction with:

Link/Unlink Timeline and Edit Selection - Shift+/

Do a search for "trim" in the Pro Tools Shortcuts Guide and you'll find some very useful commands you'll be able to add to your workflow:

Pro Tools > Help > Pro Tools Shortcuts

Shane