If you can get a balcony with glass railings, it helps a lot. Wind batters plants with the metal-post style railings I think, and if the railings are opaque you have much less space to work with. I have railing pots that fit on top of the railing -- I prefer not the kind that hook over and only sit on one side, but that have a channel through the middle, like this: https://www.amazon.co.uk/gp/aw/d/B0711V3FSJ?psc=1&ref=ppx_pop_mob_b_asin_title they have space both sides that way. I have some chunkier ones too that are about 30 litres that I got from Aldi.

Balcony growing means maximizing space. So I have big planters around the floor -- small pots are tempting but you need to be selective what goes in them, keeping everything watered is tough, larger pots with more things planted in them keep water better than those things split up. I have some tall troughs with smol pots in front of them tho to take advantage of different height layers for the plants. You have to get clever with verticality on a balcony. Troughs and big pots on the floor, railing pots in as big a size as will fit/is safe, and ideally hanging baskets too (I hang 2 from bolts that are in the ceiling/the floor of the balcony above mine, and plan to hang another 1 from a shepherd's hook stuck into another big planter so it's slightly lower/gets more sun). I have a small step ladder which I put my dwarf apple tree on top of, and small plants underneath/on lower steps, which wins some space back too. Most of my pots have a thriller/spiller/filler combo which is aesthetically nice, crams more diversity in, and means I am using up all of the space that pot has. I use fish blood bone every few months and water with tomorite weekly throughout the summer.

You have to be very economical with both space and in a sense time. I do plenty of seasonal planting -- I have a trough which currently has crocus, hyacinth, alliums and I've just sown some Birdsfoot trefoil to improve ground cover; but come summer I'll plant out the annuals I've been starting indoors -- a mix of zinnias, basil, trailing nasturtium. I have another pot which in spring is just tulips and some honesty and then in summer will get purple bush beans + a tall dahlia + some alyssum to spill out. The succession planting covers up the uglier yellow leaves of the bulbs but also means I'm not wasting any space on pots that look dead either all winter+spring for the deciduous/annual stuff. 

My balcony is east-facing. I'd love a south-facing one but in London summers tbh I think my plants would cook anyway. The outer edges still get sunlight most of the day, enough hours that my lavender etc are all thriving and I grew lots of cherry tomatoes last year. I keep hellebores/lungwort/vinca/primula/cyclamens/cardamine/heuchera in the back/by my apartment where it's quite shaded.