in ~/.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.