When I moved into my home (35 foot wide lot with a sidewalk and a parkway (grassy strip)), the lawn was Perfect. Perfectly doused with chemicals that is. We aren't the type to want to water, or spread chemicals, although I have no problem dumping tons of seed on it.
Since we live in a relatively tight neighborhood we are affected by the neighbors, water that washes up on the grassy strip during storms, etc...
Well when TruGreen Chemlawn or whatever poison sprayer stopped coming over, the lawn went to crabgrass and clover fast.
And I LOVE clover. And I despise crabgrass, because A) it eats everything else then B) dies when the weather gets cold.
So I spent a great deal of time removing the top layer of soil in some spots, and picking and picking and picking it out by the root. And now, a few years later the lawn - except the grassy strip - is mainly crabgrass free, with some good white clover and some scraggly grass poking through. I lay down a lot of seed, and my reel mower needs a good tuning so. One thing to note, in the early stages of this, the crabgrass and the clover were best friends,with the long and stringy sidewise stuff crawling underneath the clover where it was hard to see. I would pull up yards of it at a time.
By removing the direct reseeding, I seem to have taken care of most of the problem, although not all of it. Seed washes, drops, and blows onto our property and its just going to happen. The neighbors have crabgrass, the grassy strip is crabgrass (which I mow as low as possible but turns out it still seeds).
The clover, however, I know that spreads, but it does well in drought and wet conditions, and I for one really like the flowers, as do the local bees. When everyone else is watering constantly and still turning brown, I've got a low maintenance mostly green yard.
Our 150' long gravel driveway is also home to many "weeds", but I've found that a large pump sprayer with white vinegar and dish soap applied on sunny mornings goes a long way towards weakening it, if not killing it outright, and seeding has been kept to a minimum. The vinegar will kill lawn grass so it needs to be used only on areas where you don't want anything growing. Don't skip the soap, it seems to help the vinegar stick or something.