How do I pick my strains? Well I've been breeding for a long time so I look for strains to add to what I already have going on. I look for individual traits that I want to breed into what I already have. I look at breeders who have people posting pictures a lot and once in a while I see something that looks like it would fit my needs, it helps if they add descriptions of taste and buzz etc. I also pick some just to add to cross with an outdoor strain that's my own that always does well in my climate.
But even if you are not breeding the same rules kind of apply.
First narrow down what you want to have on hand to smoke. Do you really like Kush or OG or whatever. Pack your garden with what you like to smoke. Variety is the spice of life, so it's nice to have a bunch of different favorites to choose from. Something from the cookie family if that's your thing and something Lemon especially if you like the Haze stuff, find something with Gas if you like Gas, etc. etc. Eventually that way, when you are in the mood for just about any type of taste or buzz you will have it on hand.
Once you know what you feel like adding then go look for someone who has the best of it. Do you want something fruity on hand? It's nice to have some grape, right? Then go find out who's grape strain sound tasty and if it's not that great keep working till you find the pheno you want. Then bingo, you go that one covered.
That's what I do, I grow plants because I want to have jars of them in my own personal smoke shop and sometimes I just follow the work of a few breeders and decide to give them a chance based on their reputation, but I'll stick only pick strains if I feel like adding them to the stuff I have on hand or because I want them for breeding. If I've already got cookies or diesel or stardog etc, on hand I'm going to pick something else. Sometimes I just get sick of smoking something and don't grow it for a while, but I always have at least a few good examples of all the basics on hand.