My git setup

git_setup.sh

git config --global init.defaultBranch main
git config --global alias.clone 'clone'
git config --global alias.br 'branch'
git config --global alias.st 'status'
git config --global alias.co 'checkout'
git config --global alias.ci 'commit'
git config --global alias.pr 'pull --rebase'
git config --global alias.pa 'pull --abort'
git config --global alias.rc 'rebase --continue'
git config --global alias.rs 'rebase --skip'
git config --global alias.ra 'rebase --abort'
git config --global alias.ma 'merge --abort'
git config --global alias.mc 'merge --continue'
git config --global alias.cp cherry-pick
git config --global alias.poop "stash pop"
git config --global alias.ae 'commit --amend --no-edit'
git config --global alias.ls 'ls-tree --full-tree -r HEAD'
git config --global alias.fix 'reset --hard @{upstream}'
git config --global alias.hist '!git --no-pager log --pretty=format:"%h %ad | %s%d [%an]" --graph --date=short --max-count=10'
git config --global alias.sort 'for-each-ref --sort=committerdate refs/heads/ --format="%(HEAD) %(color:yellow)%(refname:short)%(color:reset) - %(color:red)%(objectname:short)%(color:reset) - %(contents:subject) - %(authorname) (%(color:green)%(committerdate:relative)%(color:reset))"'
git config --global alias.thist '!git --no-pager log --pretty=format:"%h %ad | %s%d [%an]" --graph --date=format:"%Y-%m-%d %H:%M" --max-count=10'
git config --global alias.save '!git add -A && git commit -m "WIP SAVEPOINT"'
git config --global alias.broken '!git add -A && git commit -m "BROKEN WIP SAVEPOINT (Something does not work in this commit)"'
git config --global alias.sur 'submodule update --init --recursive'
git config --global alias.ssr 'submodule status --recursive'
git config --global alias.standup 'log --pretty=format:"%h %ad | %s%d [%an]" --graph --date=short --since="24 hours ago" --branches'
git config --global alias.vendor '!f() { git submodule add git@$(echo $1 |sed 's/\\//:/').git vendor/$1; }; f'
git config --global alias.done '!f() { if [[ ! -z "$1" ]]; then git checkout $1 && git branch -D @{-1}; else echo Branch name can not be empty; fi;}; f'
git config --global alias.ff '!git diff-index --quiet HEAD -- && git fetch && git reset --hard @{upstream} || echo Aborting because of unstaged changes...'
git config --global alias.search 'log -p --all -S'
git config --global alias.regex 'log -p --all -G'
git config --global alias.contains 'branch -a --contains'
git config --global alias.pf "push --force-with-lease"

git config --global --replace-all core.pager "less -F -X"
git config --global --add merge.ff false
git config --global remote.origin.prune true
git config --global clean.requireForce false
git config --global push.default simple
git config --global pull.rebase true
git config --global submodule.recurse true
git config --global --add --bool push.autoSetupRemote true
git config --global rebase.autosquash true

sudo git config --system core.untrackedCache true

git config --global color.ui true
git config --global color.diff-highlight.oldNormal    "red bold"
git config --global color.diff-highlight.oldHighlight "red bold 52"
git config --global color.diff-highlight.newNormal    "green bold"
git config --global color.diff-highlight.newHighlight "green bold 22"
git config --global color.diff.meta       "11"
git config --global color.diff.frag       "magenta bold"
git config --global color.diff.commit     "yellow bold"
git config --global color.diff.old        "red bold"
git config --global color.diff.new        "green bold"
git config --global color.diff.whitespace "red reverse"
echo -e "\n# ᐃᐃᐃ If this commit is applied, it will... ---------------72 chars----|\n# ᐃᐃᐃ What is this ? Why was this change made? ---------------------80 chars----|" > ~/.gitmsg && git config --global commit.template ~/.gitmsg

To handle https submodules in a repo:
git config url.ssh://git@bitbucket.org/.insteadOf https://bitbucket.org/
git config url.ssh://git@github.com/.insteadOf https://github.com/

If you have trouble setting a git config use --replace-all ex:
git config --global --replace-all alias.co 'checkout --recurse-submodules'

Kdiff3 Diff/Merge Tool

git config --global diff.tool kdiff3
git config --global difftool.prompt false
git config --global merge.tool kdiff3
git config --global mergetool.prompt false
git config --global mergetool.keepBackup false
git config --global mergetool.keepTemporaries false

p4merge Diff/Merge Tool

git config --global diff.tool p4merge
git config --global difftool.p4merge.path '/Applications/p4merge.app/Contents/MacOS/p4merge'
git config --global difftool.prompt false
git config --global merge.tool p4merge
git config --global mergetool.p4merge.path '/Applications/p4merge.app/Contents/MacOS/p4merge'
git config --global mergetool.prompt false
git config --global mergetool.keepBackup false
git config --global mergetool.keepTemporaries false