Create a branch and make some changes

git checkout -b feature
git add .
git commit -m "some changes"

Make some progress on the master branch:

git checkout master
git add .
git commit -m "progress"

Observe the situation using gitk --all &

$  git checkout feature
Switched to branch 'feature'

$  git rebase master
First, rewinding head to replay your work on top of it...
Applying: feature

Observe the situation again using gitk --all &