Flagstaff is still pretty wet and there is snow above 7500' on most trails but the lower elevation stuff is mostly dry. Unless we get another winter storm (what is the chance of that?) most everything should be open by April.
There's lots of dispersed camping off Schultz Pass Rd with great proximity to many trails. However, most FS roads will still be closed. Check here for updates: http://www.fs.usda.gov/detail/coconino/ ... rdb5339811
Otherwise, there is good boon docking and easy access to the Fort Valley Trail network from the western TH located of FS 164B. It is open to the TH and a bit further past and there is lots of easy camping. If the gate is open there is even better dispersed camping off FS9002. Friedlien Prairie Rd will still be closed as well most good camping in the aspens off of Hart Prairie Rd or FS418.
As for Sedona, the primo camp spot is at the top of Schnebly Hill Rd. It's a bit rugged and can be muddy getting in there but the view is the shizzle. The dh on the Munds Wagon trail is pretty good too and you can hook it up with Hangover. https://firstname.lastname@example.org ... !1e3?hl=en
Most campgrounds in Oak Creek Canyon are still closed. IMO, here are the best locations for dispersed camping in the Sedona area. https://www.google.com/maps/d/u/0/viewe ... O5V2yvdDCU
It's more difficult to camp in Sedona with easy access to trails that are fun to ride. If you need an easy water fill-up you are more than welcome to stop by mi casa. I live across the street from Elden Lookout Rd and Schultz Creek. I'll be around in April except for easter weekend.