The prompt from Threadless was spring break, so I focused mostly on hedonistic themes and settled on these thumbs. 

I start with non-photo blue then move on to mechanical pencil. 

then fill my darks, do some rendering, and bolden lines with a 4b

After a bunch'a fiddlin around, and choosing an appropriate font, I end with this!  I desired a very flat graphic aesthetic for this piece. 

Bye, See ya later!!  And don't forget to help me out by voting 5 here: https://www.threadless.com/designs/life-of-the-party