One of my favourite cocktails is the Vieux Mot. You may need to fiddle with the proportions from that recipe a bit, that much simple syrup and elderflower liquer makes for a very sweet drink. I like mine a bit tart, if it’s too sweet it just tastes sticky to me.
I also love bourbon (or whisky!) sours, more so the way my husband makes them. He uses honey syrup instead of regular simple syrup, which I think is tastier. He doesn’t do recipes, though, so all I can tell you about making honey syrup is that you put a dollop of honey in a little water and warm it up in the microwave. If it takes a couple of tries to get it right, I guess you’ll just have to drink the failed experiments 🙂
While we’re talking about variations on cocktails, try adding cherry bitters to a gin & tonic if you can find them. Seriously, it’s really good.