Control the corners,
The resonant frequencies from your rooms 3 dimensions congregate in the corners, and such managing the sound in these areas will give you the most effective results for the acoustic foam you use.
Dont be afraid of them.
Despite our best efforts speaker and subwoofer placement is often dictated by the room layout rather than the ideal position from an audio perspective.
By using bass traps and other acoustic foam tiles you can reduce the impact that the corners have on your audio set up, enabling you to get the most from your equipment.
Foam specs:
25kg/m3 density.
Absorption Coefficient 0.85 @ 1000KHz, >1.0 @ 5000KHz
Fire safety: PASS The Furniture and Furnishings (fire) (safety) Regulations 1988 (as amended).