Thinning is a learning curve all gardeners have to go through SD no doubt pruning fruit tree's is too.
I found it alot easier to cull plants in the GH, this year, you have to choose the best and send the rest to the garden in the sky in order to make enough room for the chosen few.
Same with veg. I grow in modules then plant out, and this year, was determined to thin to one plant per module no matter how many seeds germinated.
I found in the first few years of growing your own, at the start of the year you conveniently forget how much room each veg needs, I'm still learning, thinning is more ruthless and veg spacings are getting bigger so the crops are getting better