The trick is knowing what to pull out and what to leave. It's hard to tell at first, when things are just sprouting. It all looks green and promising until the leaves start to take their mature form.
After years of gardening, I'm pretty good at telling the difference. I can discern which humble beginnings will bear the fruit I intended and which will choke the life out of everything good. It took some mistakes to get here, but in the garden it's pretty easy.