Here's another sickle I've made so far. This one is probably the most sickle-shaped sickle out of the 3 attempts.

The other neat thing about this sickle is the fact that it has serrations!

Each and every single tooth was filed in at an angle to give it similar edge geometry to the main bevel of the sickle itself. The sickle itself is a single edge bevel. It grabs the grass a bit better than a standard sickle, and it goes through much more dry and stiffer plants too.

The blade was forged from a section of lawn mower blade and the bevel was forged in. The whole sickle had to be bent inward more than the curve you see in the picture to compensate for the material stretching under the hammer blows. An edge was pinched out with the round face of my rounding hammer.
The sickle is not hardened at all, it's left as is to make filing easier.

The handle is nothing more than a spare handle I found lying in a drawer, it probably came from an old garden trowel, so it suits the blade rather nicely.