After reading both sites, I've got a pretty good idea now of what to do. John's table of absorbing coefficients were really interesting and really put a lot of things into perspective i.e (how heavy curtains do hardly anything for absorbtion under 4khz etc)
Whats of course very important is bass trapping, I dont want to kill all the highs and make it sound too boomy. However, placement of bass trapping can be tricky. I thought it'd be best to show you the pictures of both rooms I am treating. Both rooms as you can see are very different.
Ok, so firstly this is the 2nd live room underneath my control room. It doubles and a rehearsal space and live room.
Apologies for the mess, thats the last thing on my mind right now! haha. The two traps on stands are just experiments. They were upstairs in the control room but I'm just seeing if they'd help downstairs.
Here is another angle
As you can see I've attempted a mixture of hard and soft surfaces in a checkerboard pattern but unfortunately I'm low on the left over auralex foam that I bought for my home studio years ago..
There are two windows to the right for soundproofing. Thats simply got 2inch fibreglass in a frame covered with material.
Below here is from the opposite end. Those foam auralex bass traps in the left corner wont be staying there! The right hand corner has a door which leads to the kitchen so its difficult to bass trap there.
There are plenty of options for bass trapping the ceiling and atleast 3 corners of the room but I wanted to get a few pointers if you guys may find it interesting!
I'll post the 2nd live room in another post.