Linux find files by name, size or age and delete them safely

find . -name "*.log"                     # by name
find /var/log -type f -size +100M        # larger than 100 MB
find . -type f -mtime +30                # older than 30 days
find . -name "*.tmp" -type f -print      # preview first
find . -name "*.tmp" -type f -delete     # then delete (cannot be undone)