I haven’t picked out a souvenir yet.
Are you visiting a neat place? Grab some dirt and bring it back with you. Then pretend to give birth to it in front of your friends. That dirt is now a special souvenir! It's the best present you could ever give someone!
These readings are exceptions, sorry! Here's a mnemonic to help you:
When someone asks you who gave you a souvenir, just say "Miya gave (みやげ) it to me." Who's Miya? No idea. But neither do they. You never have to remember who gave you anything ever again! Miya gave you everything you own. She's probably a great person.