There is no such thing as a maintenance-free landscape. Unless you just want straight-up concrete. But there are a few ways to reduce the time spend on your garden and landscape maintenance.
1) Avoid putting grass next to rocks, steps, fencing, etc. This will create a constant need for weed eating. Anytime you have a vertical surface against grass you will have a weeding maintenance issue. Like what is pictured below:
Right: You can see where the grass growing against the boulders creates a maintenance issue, it will almost constantly need to be trimmed.
Left: Adding an edging material like the concrete edging pictured above would reduce the need for weekly trimming. The trimming would not be needed because when the grass was mowed it would also take care of the edge trimming, therefore, eliminating the need for trimming.
2) Eliminate small unnecessary grass strips. Above: You can see the strip of grass above. This is a lot of work to mow weekly as well as keep the edge nice straight and crisp. Eliminating this strip would make the weekly maintenance much easier.
3) Identify Problem Areas. These are areas where you spend a lot of time maintaining. For example, if are you ALWAYS weeding “that” ground cover or other problem plant replace it with another one that would work better for that specific location.
4) Identify the plants that work for your garden. There are plants that regardless of the neglect we give them they still look great. They keep the weeds down around them they stay the desired size and they don’t need much deadheading. Reuse these plants. For me and my garden some of those plants include Daisies, Ajuga, Daylilies (just don’t let lawn grass get tangled up in them), Obedient Plant (Just be warned of the reseeding) and even African Zinnias (which are annuals, but in my experience, they don’t need much weeding). These plants because of their nature are not for all situations. Some are very aggressive and will choke out plants around them (thus the reason they are also great for week control, unfortunately sometimes they become the weed). To learn more about how to choose plants read this article Tips for Placing Shrubs in Your Garden and Landscape