There's a lot of variants, but a couple of the most common ones are:
1) "Welcome to ScamCo! Here's a check for $X to help you pay for these work supplies, send us back the extra after you're done." (The check bounces; the repayment of the remainder doesn't.)
2) "Welcome to ScamCo! You'll be my personal assistant, please buy me some gift cards / cryptocurrency / whatever." (The payment to cover the cost of the cards bounces; the gift cards / cryptocurrency / whatever are unrecoverable.)
3) "Welcome to ScamCo! You'll help me move money between my bank accounts." (The bank accounts are stolen; the mark is working as a money mule.)
4) "Welcome to ScamCo! You'll help us reship packages." (The packages are stolen goods.)