Summer is a good time to use the chop and drop technique to add new organic mulch, you can shallow dig in compost or manures, spread mineral pH adjusters/ soil conditioners such as lime or sulfur, you can add to any mulch that has begun to deteriorate (as it should).
In short, there are lots of things to do soil building wise, what really determines what you do is what does the soil need Right Now?
Mother nature does not take days off, she is always building her soil.
We just observe what she does at any particular time, and thus learn what we should do at that same particular time
If you have the materials, why not do some lasagna mulching (layers of different compost materials over cardboard) where you want new garden beds.
We use this method anywhere from 3 months to a year prior to opening a new garden bed. By opening I mean putting in the first planting of crops.
One of the items I have become a grand fan of is a product called Sea-90, sold by the Sea agri company seaagri.com.
This can be used several ways 1) as a foliage sprayfeed, 2) as a ground watering, 3) spread dry over the soil and around trees and garden beds.
We use it for pasture soil feeding as well, it is amazing how the animals show a marked preference for the pasture plants grown where we have applied this stuff over non treated areas.
It also makes vegetables much more flavorful to our palates.
Raised beds can be use any time and just about anywhere.
We use them to get extra depth for root crops and we use them where the soil would take a lot of amendments to get fertility up to snuff.
We also use them to help keep roots from competing with the orchard tree roots since we plant vegetables in amongst them to better use all our space.
Double digging is useful when the soil is deeply compacted, starting out in a rocky area for being able to grow deep root crops, adding amendments to loosen soil.
My wife subscribes to double digging, I do not prefer it since it kills the microbiology of the soil. We do use it where it will be beneficial in the long run to have most of the rocks out of the bed.
I then spend the time to rebuild the soil microbiology as quickly as is possible through compost teas and mychorrizal inoculation.
Sheet mulching builds soil, aids in microbiology strength, suppresses unwanted plants and prevents dormant seeds from sprouting.
You can plant directly into a sheet mulch in most cases.
The great thing about these methods is that you observe first then decide which method will do the most for the space you are working on.
Usually I find that a combination of methods will be the best fit for the most benefit.