I don't know your goals and such but tequila, seltzer, ice with a squeeze of lime is a good "go to" drinkie if you want to keep an eye on what you're imbibing.
Edit ---> For your three questions IMO: Diet Soda - no. Real Soda - no unless it's a Moscow Mule, or whatever, as the ginger ales I see in my bars are only a few ingredients - ginger ale mixes really well with all booze. Juice: yes. From low to high on the sugar scale: grapefruit, orange, apple, pineapple, grape <--- End Edit
When I do go out and want a drink it's:
I will only incorporate juice if it's a poncey bar that's muddling or will fresh squeeze - I live in NY so that's quite prevalent. Or I'll just stick with a nice seltzer, ice, and a couple dashes of bitters.
Note: I drink like a gun totin' dame so it's usually neat: bourbon or rye, on occasion vodka on rocks or a good martini :) Oh! That all gets thrown under the bus if champagne or prosecco appear, which makes me swoon in happiness.