Hammocks can be made with clips attached or only tabs for detachable clips. Metal clips can chip the enamel inside a washer or dryer. I find I need several, one is always in the wash.
For these projects I used
Polyester fleece stadium blankets from the thrift store for $2.00 each
Polypropylene webbing from a belt strap cut into 4" pieces.
and 4 swivel clips from an old purse (they don't HAVE to match)
cheap shower curtain hooks
Step 1: Make a template or paper pattern
Or you draw something freehand.
Or cut a template from cardboard, this is best for rectangular ones.
Keep reusing the cardboard template to trace new ones.
For this particular design I made half the pattern, so that I can cut the material folded.
These are both 15 inches long by 13 inches wide, though they can be made wider or even smaller to fit smaller cages. I find with this size i can actually get TWO into one cage on different levels.
If you are making the 'sling' style, be sure to make the corners taper to no less than 4 inches wide to allow for webbing AND the turn.
Step 2: Cut out material
Trace and cut out TWO sides.
leaving 1/2 to 3/4 inches for the seam allowance.
If the top and bottom don't match perfectly, they can be trimmed AFTER you sew,
but it won't matter because it will be inside the hammock.