~/.cargo/config you can switch to lld as a linker (needs to be installed of course):
[build] rustflags = ["-C", "link-arg=-fuse-ld=lld"]
Linking often took the most of my time when just changing a small amount of code, so the above has a big impact on day-to-day work.
If you don't need debugging symbols often, you can add
[profile.dev] debug = false
For your project. This can speed up compilation times.