I definitely recommend heading over to r/cocktails and perusing for a while. And an app like Mixel or the PDT cocktail app are great resources for learning new cocktails and stocking a home bar.

Personally, I love a good whiskey cocktail. If I had to pair down my home bar to just 5-7 modifiers (leaving out common ingredients like citrus & readily-available syrups), here’s the approach I would take:

Sweet Vermouth (Carpano Antica Formula)
Dry Vermouth (Dolin Dry)
Amaro (Amaro Ciociaro & Amaro Nonino are two of the most versatile)
Luxardo Maraschino Liqueur
Camparai
Benedictine
Absinthe (just a small bottle is fine)
Cognac (not a modifier, but really every bar should have a nice bottle of Cognac)
With these 7 modifiers, plus a few basic bitters (Angostura, Peychaud’s, orange) you’ll be able to make some truly beautiful classic cocktails. A few of my all-time favorites:

Brooklyn
Sazerac
Vieux Carre
Boulevardier
De La Louisiane
Manhattan
Penicillin
Old Fashioned
Other cocktails you can make with this include: your Brown Derby, Improved Whiskey Cocktail, The Preakness, Rob Roy, Bobby Burns, Old Pal, Mint Julep, Frisco, Manhattan Transfer, Sweet & Vicious, Carroll Gardens, Blue Run Sling, Fancy-Free, Blinker, Junior, Rattlesnake, Whiskey Smash…

Cheers, and happ