I bought a cheap hammer and wanted a nicer grip than the bare wood. Thinking of how nice a linen wrapped pool cue feels, I decided to try wrapping this handle in cotton string.
The only tools I used were a knife, a pair of scissors (but I should have used the knife!) and a bowl of water. The only material (aside from the hammer itself) was a length of cotton string and a short piece of nylon monofilament, which I did not even have to detach from the spool.
Step 1: Carve the wrap area
I carved notches at the edges of the area I planned to wrap, to give the string boundaries it wouldn't easily slide over. I measured by simply holding the handle and marking a half inch or so past where my hand went. I drew a careful line all the way around, at each end, with a ball-point.
I started carving using my little pocket knife but soon switched to a big K-Bar which went a lot faster. I considered carving away the top layer of the entire wrap area but decided this was not necessary. I carved only as deep as the thickness of the string, leaving a sharp cut at the ends of the wrap area and gradually smoothing the cut towards the middle of the wrap area.
I added a vertical notch at each end to tuck the string ends into so they would not disturb the surface of the wrap with an Unsightly Lump.