You can clean your archlinux, with some suitable packages so that your system remain clean.
Be aware your system might not work properly if not followed properly, so backup first. Be very careful here!
Some useful commands
1. Clean package cache
sudo pacman -U /var/cache/pacman/pkg/packagename
- Cleaning the cache manually
sudo pacman -Sc or sudo pacman -Scc
- Cleaning the cache Automatically
sudo pacman -S pacman-contrib
paccache -h
paccache -d && paccache -r
2. Remove unused packages (orphans)
sudo pacman -Qtdq # shows list of all unused packages
sudo pacman -Rns $(pacman -Qtdq) # removes all the unused pacakges
3. Clean the cache in your /home directory
sudo du -sh ~/.cache/
rm -rf ~/.cache/*