There's nothing like a job where you see almost immediate financial gain when you put in a little more effort. Such a job was coffee shop waitressing night shift in a busy place where the manager leaves it up to the waitresses to seat their own stations. The aggressive waitress will grab them first and if you don't like it -- beat her to it next time. The harder you work, the more money you make in tips. The waitress who taught me that was at first (I thought!) a real witch (replace the w with a b) but we ended up bosom buddies for years. I learned a lot from her and it paid well.
I loved waitressing! I made a lot of dough and worked with a lot of Mexicans and American teens.
I also worked as a waitress for many years made a ton of money!!!! VERY RELUCTANTLY went into management, the most income I EVER made in my life for hours worked was waitressing and LOVED every minute of it!!!!