With this model I wanted to veer away from having the standard hi tech sci fi asthetic and have a basic weapon that still be used in a sci fi enviroment. To make this knife i started off with just a cube end extruded it to the right width and length. I then inserted a series of edge loops so that I could add a curve in the blade. This was done by lowering the vertices the further along the model i got.
Here is my concept sketch. 