I have day-hiked and backpacked quite a number of trails at Yosemite. A few questions:
1. How familiar are you with Yosemite?
2. Are there particular areas/peaks/waterfalls/types of terrain you'd like to see?
3. Describe your capability as a backpacker -- number of days, distance per day, how much elevation gain you can handle while carrying a full pack.
4. Do you prefer a guided or self-guided trip, and why?