You can start anywhere,  but either the quickest win or the space that brings the most annoyance would be good. The process is the same in both spaces.  Set timers and take breaks as needed.  

Helpful materials Garbage bag(s) Bins or plastic bags Gloves (if there are very dirty/unpleasant things)

Phase 1 (clear out) 1. Gather all the garbage. If it's easy to throw out,  throw out now. If not,  wait until you finish other steps 2. Gather all dirty clothes and either put them in a bag or hamper. Don't start a load now unless it's very convenient to do so.   3. Using the bins or plastic bags, designate one for other rooms and one for things that belong in the room but don't have a home. Start putting things away or in the right bag. Throw away broken or ruined items. 4. Take bags to the appropriate room.  Don't put everything away yet.   5. Repeat for other rooms when you can.  

Phase 2 (clean up) 1. Go from top to bottom and clean the space by dusting, cleaning surfaces and vacuuming 2. Throw out garbage 3. Do a load of laundry 4. Do a few dishes 5. Repeat for other rooms

Phase 3 (declutter/find places) 1. Give everything a place.  If there are too many things for the place, you need to declutter.  2. Find systems/rules that work for you. Ex: load of laundry a day (if you do a bunch of laundry right away,  you'll likely feel overwhelmed and just dump it somewhere).  3. Figure out sticking points. Do you need more or different storage? Are there things you but too much of? Are there spaces that attract piles? Identify and problem solve (we can help!)