Last time I had the time to post we told you that we use two main pieces of equipment for isometric and suspension work: either a cam strap we make into a suspension device or a Universal Strength Apparatus (actually, a USA 'Pro').
The first option will run you about $20. The cam strap suspension tool is, frankly, just as good as almost any of the 'suspension trainers' out there on the market, particularly any that have a single connection point for both handles (i.e. the TRX or old JungleGym). A picture is worth a thousand words, and a video even more, so here's how we make and use one:
To throw it out there, we consider the USA Pro to be a worthwhile investment for a few reasons. One is that you don't have to do any adjusting. This is sort of laziness on your part if it is 'just you,' but if you have this hanging in your boxing gym or other facility, it is nice for folks to just be able to walk up to it and use it. The second reason is somewhat related to the first, in that you have fixed handles to use, which makes your ISO work both much faster, and even more importantly *consistent*, both between sides and from workout-to-workout.