If you don`t have much cash then for flower you can normally buy a powdered food with a ratio of 1-2-3 npk with mag and TE cheap
When I say cheap I think its between £1 and £10 per kg depending on where you get it and how much you get, and you`ll only need around 1g per L you can step it up to 2g per L or even use half a gram
Later in flower adding potassium sulphate or monopotassium phosphate or even just some molasses or dextrose can help bulk up the buds
If you look around you can sometimes find very cheap "tomato" food, that has good npk ratios as well as TE, CALMAG and seaweed extract seaweed extract is loaded with triacontanol and other stuff that makes the plants bud up big and bush out
or there`s some really cool organic soil mixtures people on here use, stuff like oyster shell flour or crab and such, some really cool mixes people are doing that just need water and the nute break down into the plants over time
Organics can seem really lazy when you see someone that`s really good at it as they seem to do a lot less work but really its because they`ve got their soil mixture bang on and that means they have less work to do because of that
Personally I like my "soil" to be pretty much "empty" when I start I like to add the nutes and I like mostly bottles of liquid or powders to do it with, something about having to wait for a product to rot in my soil before my plants can eat it, idk just the whole idea seems far too mother earth for me, lol