"All the other steps" isn't something I would expect in a how-to list, maybe try a repeat as follows or continue to destination?

What a cool idea... :) maybe you can upload a version with a placement on a tee so we could see the whole thing... Love it!
Pls check out my Tool Belt... Thanx

How about if you just had the 4 steps total or added 2 more levels for 6 steps?

Also you could do a similar concept with the term "Fig. 01" and Just keep adding "Figures"/People across a shirt.

My other idea is to have different photos of figs on a shirt bort - I might just roll with that instead

And @tleed - you've obviously missed the point of this design. It's not about stages of instructions (as 'step x') normally indicates, but actually refers to the physical steps of some stairs.

version 2

Very clever idea, only thing I could possibly recommend is to try different shirt colors and see which ones look the best, but other that, nice work. :)

clever idea! maybe try to put it on a sheet of paper, giving it fold marks or something to have a background, even shades of folds may be enough.
If you donīt choose a white paper-like background, Iīd prefer a sand or cream tee.

if you have the time I would be happy if you could have a look here

better?