(These figures are cash, except a $100 amazon gift card; I've been doing mostly cash bonuses since I don't travel a lot.)
The end of last year while analyzing my finances, I realized that I made ~$700 from a few credit card bonuses and cash back, without really thinking about it. After hearing someone on the forum say they made over $2000 in one year from checking account bonuses, I decided to take both of them seriously. In 4 months, I've already made more than 10% of my annual salary as a grad student! Don't worry, it's all going into index funds...
6 new credit cards: $1600.
The bigger bonuses tend to come with annual fee cards and high spend requirements. Given that my living expenses are less than $1000/month (with rent and other expenses not even payable with credit cards), this would put most bonuses out of my reach. However I found a pretty easy way to "manufacture spend" about $600/week, so at this point I can do a $4000 spend in 7 weeks.
I am on a hiatus from doing more credit card bonuses, because I started having my applications declined. It takes about a year for one's credit score to stop being affected by inquiries.
13 new checking accounts: $1400 (with another $800 receivable)
These are reported as 1099 interest income, so I need to set aside 20% of it for next April. They are also a bit more complicated to do, but on the plus side, banks accept basically everyone since there's no score to get you rejected as there is for credit cards.
I follow
doctorofcredit.com, and the vast majority of the bonuses I've completed, he wrote helpful guides for. With these it's important to be really organized with spreadsheets / financial programs to keep track of to-do's and where your money is. I'm a pretty detail-oriented person so this part came pretty naturally to me.
Happy to answer any questions, and hope some other low-earners will find this useful.