I have been working on a feather wallet plugin to be able to simply perform xmr<->btc atomic swaps using the inbuilt feather GUI. It is very straightforward to use but I would still recommend reading this quick blog post on how atomic swaps work if you don't know so you understand what is going on behind the scenes.
This is also only the second release so there may still be some minor bugs in it, if you find any please post an issue on the github.
Also agreed. Having atomic swaps for BCH, LTC (MimbleWimble), and ETH would be fantastic. IMO, we don't need liquidity pools if we could have a simple UI that would allow us to say "I have 30 LTC to convert to XMR" and it allows you to divide up your 30 LTC into several XMR offers and then press "start" to execute the batch process. Sure you might only be able to convert 29.3 LTC to XMR using this method, but it would be completely peer to peer and could be done without the need for an arbitrator or liquidity pools or (if it's loaded into wallets) any separate software like Haveno that you have run on your computer. It would also allow someone to convert large quantities of one crypto into another safely without arbitrators. And if I'm not mistaken, the trade could be done in parallel so making a trade of 50 smaller exchanges would not be significantly longer than a single trade.
One of my major gripes with bitcoin is that everyone that owned it got the same amount of bch and everyone including the powers that be think its OK. Is everyone sitting down? Is monero the only coin that stands for something?
MW on LTC requires the other party to also participate, something which exchanges and most people will never do. I used to use LTC but have found BCH to be a better option with more potential in the future as the community is very active.
You can just create two different accounts, both with MW on LTC and pass coins between them to break the chain. But yes you're right, I wish it was opt-out instead of opt-in