I'm using a lot of WeMos D1 Mini's flashed with ESPeasy communicating to Node-red running on Pi's Pi Zeros and a Mac. So far I've connected DHT22s, BMP280s, OLEDs, NeoPixel rings, an RFID sensor and along with @dynamicdave, we are putting together a PCB for solar/battery weather station (see Solar-powered weather station for a sample of it)
Here is version 1
in version 2 we are splitting the battery/Wemos to one board and then we will have an I2C connector to a second board wich will have slots to plug sensors into.
I was creating a list, but @TotallyInformation has already listed much of what I would have said so I'll add
transistors
dupont wires, M/M, M/F and F/F
some blank PCB's if you want to build permanent prototypes
header pins and headers
hot glue gun,
wire shrinks.
