Of course you will need to balance the size of the job with the number of hands you have to work and the time you have. Sometimes it can be a daunting task. But weed killer can be expensive, especially on larger areas. And of course - weed killers are poisonous.
There are two approaches if your ground is going to take some time to clear.
1 Do smaller manageable pieces: Keep at it, give yourself a pat on the back when a piece is done - you'll eventually get there - see below for help.
2 A fast track mechanised approach: Perhaps you want to use a garden tiller to break in a new plot. You'll find more
about garden tillers and what they do on this link.
A thriving site - And there are worse things.
Sterile weed killed land stagnates
no that's not the shed flattened out but
some old fencing.
Weed Barriers And Sheet Mulch
First you need to remove any debris from the site - building rubble and rubbish.
If you have to clear trees and stumps see below,
Then cut the weeds down to the ground.
Increased shade and drier conditions usually leave wooded areas free of the usual weeds. That may change when a wood is cleared. Resist the temptation to clear established woodland where it provides valuable wildlife habitat.
But if you have an overgrown orchard or an area where ornamental or fruit trees have spread by underground suckers then, clearing it up can be quite a challenge.
Don't be stumped by the problem
You should not cut off the trees at ground level, but leave a good length to help you grip and lever them out of the ground.