When I started my retopology, I started doing it manually using the planes to create the new geometry. Some of this process is shown below.

I had gotten a decent way through the retopology before I realised that time was catching up to me. For this reason, I decided to copy my character and prop into another blender file and use the voxel rems tool, along with multires and shrink-wrap modifiers to do a really quick and makeshift retopology. I realised before this process that this would cause some problems with my UVs and texturing but I decided it would be better to have some textures and some wrong UVs than have no textures or UVs at all. This did cause some elements of the model to look a bit off and I had to improvise a lot but overall I managed to get it completed, which was the most important thing to me. I kept the original file with the manual retopology and I plan to go back and completely manually retopologise it in the future whenever I have more time. This really tested my time management skills and it is definitely something I could improve on.