Previously when I want to update my branch of git, I just commit new modifications again and again. This makes my branch log quite ugly.

After my colleague introduced git --amend to me, he really helps me a lot. Now, I just use

git commit -a --amend --no-edit

to update my modification into previous commit and

git push -f origin my_branch_name

to totally update my branch in remote

And, if I want to also change the message of my previous comment, I only need to

git commit -a --amend -m "Let's rock again"