Whiskey sour is my favourite at the moment. Others that I have tried and liked are Ward 8, White Lady, Southside. Making them isn't difficult, just need the right booze and bitters like you said. I need to buy orgeat from Amazon, other than that I can find or make syrups I need. And I could make orgeat as well but I'm too lazy. Also some Italian bitters are no available here.
Couple of youtube channels I've been following
and also bought Steve the Bartenders book
I migrated away from the Old Fashioned/Manhattan stuff because it got too sweet for me and I liked the sour stuff. It also takes some time to prepare (especially if you try and smoke it), so I didn't like how much time I was spending making cocktails vs actually socializing.
I do like sours. My wife especially likes them as well and so does my father in law. But I don't always have eggs on hand and I don't like having to screw around with storing the unused egg yolk or an accidental broken yolk in the whites while having a party, even though removing it is as easy as having a plastic water bottle. I'm lazy for pre-making it and egg whites in a carton is kinda gross to me.... but I think I'm at the point where maybe I'll start doing it a bit more and whether it's whiskey sour, pisco sour or Yuzu sour or any of those variations, I can make it for them.
My go to cocktail recipes lately for friends are French 76, Gimlet and Gin and Tonic. I often do variations of these recipes and I've often created many successful variations of these by adding splash combinations of orgeat, rose water and yogurt drink (ie: Yakult). Many friends love it and laugh when they're like, "Hey DoubleF, another one of the purple milky colored experiment please!" (I use Empress Gin which is Royal Blue but turns sorta crown royal bag purple when mixed with something acidic).
I only made the Aberdeen Angus once or twice more than a decade ago (literally learned how to make it from an anime episode I watched) because most places/bartenders refused to attempt to make it, and just gave me rusty nails instead (I guess they didn't have honey or enough lime?). But TBH, when I made it, I quite enjoyed it, even though I could taste an imbalance of the flavors due to my lack of familiarity with cocktail making at the time (had too much lime juice and honey wasn't melted enough). It might be time to circle back to this one and make it a regular part of the repertoire. No thanks to rusty nails though. Rusty nails remind me of fireball with less ridicule.
I would recommend aiming to make it slightly hotter rather than just warm though. It's a really refreshing warm alcoholic drink in a category that IMO is too dominated with drinks that are sweet with little variation. Most of them are also just other hot beverages "with a kick" so it's kinda bleh there as well. I'd argue if you know someone who knows their whiskey or isn't completely a whiskey fan, this is a good drink to adjust a scotch/whiskey that isn't completely to their liking, to flavor closer to their liking. It just feels like a good type of drink that you can enjoy that just seems to have a form of warming recovery type of effect.
I think I'll make more Aberdeen Angus and sours going forward.
Don't get me wrong, a rusty nail is a lovely drink to use up a really shitty scotch. I have bought one or two of those in my day.
It's too characteristically close to a sweet brown liquor to me. Some have said it reminds them of a lower end old fashioned/Manhattan depending on the base whiskey. But without citrus being added, I personally feel like it has a lot of bite that is intentionally hidden under sugars, so it reminds me of shots of fireball instead.
I'd never make a rusty nail ever again (whiskey and drambuie only). I'd at least toss in a splash of citrus (ie: bottled lemon juice) and attempt to pawn it off as a low end Manhattan/Old fashioned variation without bitters. (the Drambuie sorta qualifies as a simple syrup).