I'm about to set up my first studio for mixing. It's a small, roughly sqaure room. I want to set up enough treatment so that I can be comfortable that the acoustics of the room are not affecting my mix to any noticeable extent. Of course there are numerous articles and examples on how to do this on the net. Here is a good one: The Studio SOS Guide To Monitoring & Acoustic Treatment But, I'm not going to be able to afford to do everything. For starters, I live in a rented place so I can't put holes in the walls etc. So my question is: what are the most important treatment points? Room corners? Mirror points? Ceiling treatment? If you were about to set up a small square room and had a limited budget, and limited space, what would you do first?