I will be adding to this over the next week or so.
If you are planning on planting a yew hedge this autumn, now is the time to start preparing the ground. Mark out the area you are going to plant - bareroot yew hedge plants are always planted in a single row in a trench about 60 cms wide - so that is what you are going to weedkill.
Ugh! However, this is the number one month for weed seeds ripening, falling to the ground and waking up in Spring. It really pays to at a minimum hoe (and preferably hand weed) borders, rose beds, veggie patches and the like. Get your weeds before they get you. Collect them up and either take them to the dump or burn them. DO NOT put them on the compost heap - we had a gardener when I was a lad - Mr Carter - who used to say (in a broad Kentish accent) "One yur's seeds is suvun yur's weeds"....
Apply a non-residual weed killer (one containing Glyphosate is fine) following the manufacturer’s instructions anytime between now and the middle/end of September. The sooner the better as it works best on plants in full growth and you also get a chance to spray a second time to get the stubborn b*****'s like bindweed.
If you do not like chemicals, then lay ground cover fabric, black polythene, old carpet, broken down cardboard boxes (anything that will keep out the light and stop plants growing through it. That will kill anything except Japanese knotweed and horsetail by the time you get to planting in November.
And that is it - the hard digging happens later.
If the soil is soft enough for you to push a spade in full depth then you do not need to dig the ground at all. If it harder than that, then dig over short strips and rotavate long ones. Remove large roots and big stones.