
I had a bit of trouble making mine (And then explaining how I made it to the people who asked...) so I thought I'd make a proper thread, with pictures of each stage, to make it a bit easier to understand.
**NOTE - Pictures will be up tonight, or later this week, as I need to get edging tape for my demo hammocks**
INDEX
This post contains How to Make a Pocket Hammock. (Easy)
Post Two will show Variations on the Pocket Hammock. (Easy to Medium)
Post Three will show How to Make a Tube Loft. (Easy)
Post Four will show How to Make a Double Tube Loft (Hard)
Post Five will show How To Make A Corner Hammock. (Untried)
Post Six is reserved for future How-To's, and User Suggestions.
How To Make A Pocket Hammock.
A pocket hammock is the simplest hammock to make, and the most commonly found on sites offering rat toys and such for sale. They can be made in many sizes to fit your cage space, but I find that (For my five rats) a finished product of around 30x40cm works well in my cage.
Step One - Your Material.
The material you use for your hammocks needs to be non-frayable. Since rats love chewing, they will eventually "ventilate" any chewable items you give them, and frayable fabrics can leave threads that can wrap round rats, and cause injury. This is most important with young ratlets, where it can have serious consequences. The best material that I've had suggested to me (And which I use) is polar fleece. It's warm, snuggly, won't fray at all, and it's also easy to sew. Another good addition is edging tape. It's a thin strip of cotton (about 2-3cm wide) that you sew around your seams to protect them from teeth. It also makes the hammocks look a lot more snazzy to finish with. Typically, I use one 5m roll between each two hammocks/tube lofts, although the specific amount varies between each design.

Step Two - Sizing.
For a pocket hammock, I find the best size in my cage is 30x40cm. This needs a piece of material that is 70cmx40cm to make it. If you want smaller hammocks, feel free to adjust the length and width to suit your cage. (Remember that these hammocks do best with all four corners secured solidly) When measuring for your hammock, remember that the hooks and tags you use to hang your hammock add length! Measure where you want the hammock, then subtract 5-7centimetres to allow for this.(It doesn't really matter if your hammock is a little loose, and a little loose can be better than pulled to stretching point.)
Step Three - Making your Hammock
First off, you'll need to edge one of your short sides with edging tape. The easiest ways to do this are either to pin it in place and sew both sides together, or to sew it first to the left side of the fabric, then the right.

Secondly, you need to fold up your edged short side to within about ten centimetres of your other short side. This creates a pocket, and usually makes the entire hammock almost square, depending on your measurements.

Once that's folded up, pin it together, and sew around the edges of the entire rectangle (Not the edges of your pocket!). This will sew together three edges of the pocket, but will leave the one that you've taped unsewn as the entrance.

After you've sewn around the entire hammock, it's a good idea to edge it. Measure off enough edging tape to match each side of the hammock, and sew them in place. (It's okay if they don't quite match up at the corners, that gets covered next.)

(That's Tea "supervising")
Lastly, you need to be able to secure the hammock to your cage. For some of mine, I use S-hooks which I was sold with hammocks bought from The Dapper Rat. (see website links) I think you can also get them from local hardware shops. If I've run out of the hooks, I also use cable ties. There are two ways to get the hooks or ties in the hammock without damaging it. The first, is to punch eyelets in the corners of the hammock. This is best done by a professional company, and I have never tried it. The way I use, is simply to sew loops of tape to each corner, over the edges of the tape already in place. Again this can either be pinned into place first, or sewn on one side at a time.

Tada! You should have a hammock that looks like this. whee

It's a good idea to wash it before you give it to your ratties (Sometimes there are dye residues, and it stops your material shrinking in the wash, later. Poar fleece doesn't, but if you're using something else, it may.) Hang it up in the cage, and watch your rats enjoy. ^^
