azzy, the different areas/rooms have very different acoustic requirements.
The drum area needs to be live. A vocal area needs all the early reflections gone.
You don't have to extensively treat the recording areas. Just kill flutter. Use the rooms foibles to your advantage. e.g. Drums in a corner get a wonderful bass boost. A cloud over the kit will be very helpful.
The mixing area will very likely be highly treated. 2-4 inch panels of 6 pcf can be wrapped in fabric and should be stiff enough to be self supporting. This will be useful for controlling flutter anywhere. They will be useful for creating a Reflection Free Zone in your mix area.
A cloud over your mix area will be very important. Go for a thick one, 4 inches plus a 4 inch gap. FRK on the side facing the ceiling. No harm in having carpet or area rugs there also.
IMHO measurement is not at all necessary. Your time and effort would be a lot better spent learning the basic acoustic principles at work. Ears, handclaps, your own voice, can all be used to figure out what is going on locally. A lot of the treatment can be very certainly applied, based only on visual observation and a basic understanding of the physics/acoustics.
For DIY treatment details try
studiotips - tips on studio design, acoustics, and wiring
Lots of articles on how to set up the mix room at realtraps.com and gik.com
DD