If you want to use the gitalias file, and also want to customize some of your aliases, then one way is to use your git config file to include the gitalias file, then define your own custom aliases.

Later aliases take precedence.

This section has examples that include the gitalias file, then define a custom alias.

Example to do your own custom status message: Git alias:

[include]
path = ~/.gitalias

[alias]
s = status -sb

Example to do your own custom log summary: Git alias:

[include]
path = ~/.gitalias

[alias]
l = log --graph --oneline

Example to do your own custom pretty format: Git alias:

[include]
path = ~/.gitalias

[format]
pretty = "%H %ci %ce %ae %d %s"