No more room for fans :(

Hi, I have run out of room for fans on my case. I would like to tell you the specific case I use, but it is about 4 years old, and I can't for the life of me figure out where I would find out the model . Anyway, I have pretty good fans, but I need a few more. I am going to get expansion slot fans but again, I need some case fans. I am thinking of cutting a few holes in the case to fit them. Any ideas on alternatives, or how I would go about perferating my perfect case? And no, a new case is not in my budget at this point in time .
Thanks