After mowing, this can be a pain. The problem is that unless you've straight edges (I don't like them), there's the chance of "border creep," where you gradually lose a bit of your lawn every time you edge the lawn. I overcame this problem ten years ago over a couple of days. Anyone could do it. Our main border slopes to the back and I've always had a channel between it and the lawn to give a "hard edge." I bought a quantity of small rectangular block paving bricks. I deepened the channel and laid some "small" hardcore. Then I laid some damp fine concrete mix on top to a depth of three inches and about six inches wide I worked the bricks part way into the mix, hard up against the edge of the lawn, using a straight edge "over the next one and the previous two" if you can understand me, to make sure they were level. It's best to keep stepping back and surveying your work. I let it go off overnight then made up some damp sand and cement mortar, but added a but of yellow dye to "soften" the look. I pointed up the bricks, then added more mortar to make a slope down from near the top of the bricks to the edge of the concrete for extra stability. The finished product, including rings of bricks around the three features, were a "bit in your face" to start. But over a few months they settled down. Here I took the opportunity to get rid of the bits of York stone and tidy up the effect. As I made it smaller I had to add more grass, but it soon matched in. Now mowing is much quicker I just pass my Flymo over the bricks. On the otherside of the lawn it meets the path on the same level. So I just angle my strimmer and run it down the "joint." I gave the small front garden the same treatment. After ten years I never give them much thought.