Who uses cash anymore?...
We keep about $300 cash at the house. DW and I draw from it as needed. We use it for things like parking fees at concerts and sporting events. DW uses it for donations at various events, like a fund-raising yoga class that she attends every week. We also use it at the local Farmers Market and similar arts festivals, etc... partly for convenience and to keep costs down for small vendors, but also because I don't fully trust those little iPhone attachments. We also use a lot of cash when traveling outside the US.
I replenish the stash as needed, typically once or twice a year. I use the ATM at our neighborhood CVS and Fidelity refunds the $3 fee as soon as the charge hits.