I would like to make one edge sharp, and for the tip to be sharp as well. I've considered using the bevel tool, merging vertices, or just scaling things down to almost no distance. What would be the best way to make a sharp edge/tip?
There are many ways to do this. It's important to keep Quad topology with practically everything you model. This will keep you from hating life when you're 3/4 of the way through your model.
Here's a simple method to get you started:
1.) Create a plane and subdivide it. Use Proportional Editing to curve your blade:
2.) Add a Mirror Modifier to the plane and select "Merge" and "Clipping" options.
3.) Alt select the blade edge and Translate them toward the center of the mirror. Then, using Proportional Editing, Scale in the spine toward the tip.
4.) Alt select the Spine edge and Extrude it toward the center of the mirror.
5.) Apply the Mirror Modifier at this point and then create a quad out of the remaining vertices of the tip.
6.) Alt select the blade and the two edges of the spine (if you want, the two main ridges that run down the blade also) and create creases by pressing Shift + E, then press 1 and Enter. I have given the blade a Subdivision Modifier also: