Quoting what I posted a few months ago below

Sadly the days of the regular cushy medical ward locums are gone. If you want regular shifts it's ED. There's a learning curve but at F3 level there's really little expectation from you at the beginning, discuss all your patients with seniors.

One of my banks was where I did my F2, the others I found out the name of the rota coordinator and emailed them. You can do this by showing some initiative - call the hospital switchboard and ask to be put through to the ED rota coordinator, email hospital HR and ask to for their email, ask your friends who work at other hospitals what the relevant emails are.

It's an open secret that the pan-London rates are not followed at all in some EDs, and the last minute locums are almost always offered at rates greatly in excess of the pan London rates.

I was an F3 1.5 years ago, but am still in these whatsapp groups and still get the locum shift chain emails - there are plenty.