>> I'm working on new gardens in a completely unlandscaped large lot so could use some ideas!
A thought for long-term improvement -
If you have some spots that you know you won't get around to for a couple of seasons, ripping up the sod ASAP, flipping it over, and planting small patches of cover crops could save you a lot of work and cost, later, amending the soil and weeding.
You probably would even reduce the number of weed seeds "in the bank" when they sprout but are out-competed by the cover crop.
The cover crop roots will break up and enrich anything they can get into, and many cover crops reach deep, capture minerals, transport them up near the surface, and then release them when they die. And of course the tops make great green compost either in place or enriching a compost heap with something you know is weed-seed-free and herbicide free.
If "Colorado" means "sandy soil", the cover crop will add much-needed organic matter and water-retention.
Clover, fall rye, mixes with peas - there are so many options that a good idea is to find a farm coop or feed store near you, and plant whatever they stock the biggest bags of. They'll know what does well in your micro-climate and for each season.
Or pick some inexpensive native vegetation that you know you can uproot and be rid of when the time comes to plant there "for real", and start it in a few spots to compete with weeds and build up organics.
If you start by buying plants instead of seeds, buy 1/10th as many right now, and multiply them yourself so that when you want to populate more plots, you are your own nursery.
