Hi there, I'm a professional landscaper, Gärtnermeister operating in Germany.
Lawns are a bit wasteful, but are the lowest maintenance option for your property outside of letting the wilderness grow back. They look great when they're doing well, and provide a wonderful backdrop for the house and other plantings. They need not be expensive.
Herbicides and pesticides are not needed for a healthy lawn. Keyword healthy. Provide a good base for your grass to grow on, and it will do its thing. 15 cm of well-worked balanced soil with good organic content will do the trick. Incorporate humus or well-rotted compost into the ground before planting with a tiller, or after planting with an aerator and topdressing. Pesticides and chemical fertilisers will damage the soil ecology that will help your grass.
Maintenance is key - lawns like to be cut high and cut often. Mow every ten days or so, and leave it high, at least 7 cm. The grass species in your lawn are not the same as they use on golf courses, and can't take being cut short. This mowing technique keeps the stress on the grass to a minimum, and allows it to defend itself against weeds and pests. Mulch the grass when you can, this cycles the nutrients back into the soil.
Accept the fact you're going to have weeds. A perfect monoculture of grass is only achievable with heavy chemical inputs (think golf courses).
Water correctly - frequent light waterings encourage surface roots, making the grass prone to drought damage. Water once a week at the most, and thoroughly, about 3 cm (use a rain guage).
If you want to get really environmental, you don't need a mower at all. There is a pretty slick rotary push mower from Fiskars that does a good job, trimming you do with special grass shears. You can even do it with a scythe (pretty meditative work!).