Stitch Markers, Needed or Unneeded?

[Crumpets]

So I recently started crocheting a shirt (I'm a beginner) and its my first project. The tutorial says I should use stitch markers for the sleeves to mark where I stop. For reference I'm making a sorta crop tank top. I was wondering if I need to use stitch markers? Or if theres a substitute as I dont have any.

[bgs]

Safety pins, bobby pins, earrings, paper clips, wire bread twistie, zip ties, and even a scrap of yarn

[Netzel]

Yes, you should use some sort of marker according to the patterns instructions  As bjs suggested, I’ve used little pieces of scrap yarn in a different color and safety pins. Enjoy 

[Granny Square]

A little late to this, what everybody said above--you don't need to go to the craft store to buy special markers.  I use bobby pins, they rarely fall out, don't snag, and are super inexpensive if you do happen to lose one (like 1-2 cents each).  If a pattern tells you to put a marker in a specific place, fine, you know what the marker means; if you are putting a marker in for your own reason, make a note of what the marker meant, so you aren't wondering if you put the project down and come back to it days later -- did I mark the first or last stitch of the round? for example.