I use the PayPal Here card reader. With the latest machine you have the tap and go contactless payment option for goods under £30 GBP in value. Some of what I make I sell to my workmates and the tap and go option is popular as they don't need to go fiddling around for cash. As long as their bank card supports contactless payment they can do it. The reader also has a slot for chip and pin payments for any value transactions as well. I think I paid about £50 for my reader.
I chose paypal here because I also sell on Etsy and sometimes Eb*y and paypal can be used for all platforms and for international currency sales so it covers pretty much anything I currently need. Yes, I know they take their cut but it saves me a lot of hassle especially on international currency transactions!
The only problem I had was, at first my old android phone would not support the app software. But after changing my phone to a more updated model it works fine now.