regard to fertilizer.
2. Leave the clipping on your lawn.  This will add valuable nutrients.  Don't leave clumps of grass.
3. Water in the morning longer and less frequently.  Most lawns need 1/2 to 1" of water/ week.  Watering at noon every day is just going to put more water in the air through evaporation.
4. When you cut the lawn leave the grass at about 2-3".  Shorter grass is more susceptible to heat and stress.
5. Use many types of seed in your lawn.  A variety of grass is better.  If you have all one variety and that variety gets sick, your entire lawn can die.
6. Fill bare spots.  When you have a bare spot fill it with seed.  If you have grass growing instead of weeds your lawn will look better.
7. Fertilize with an organic fertilizer.  Also fertilizer twice a year once in the spring and again in early fall.  Remember tip 1 before you use any products on your lawn.
8. Some weeds are not bad.  The image of the perfect lawn is not real.  Clover and dandelions in a few spots are not reason to treat your entire lawn with a chemical.  If the weeds still bother you spot treat them, not all your grass.
9. Sharpen blades of mower. Sharp bladed mowers cut and don't shred the grass.
10. Aerate the lawn if thatch gets too thick.  If you have a lot of dead grass it is a good idea to have the lawn aerated and dethatched.   This will encourage a healthier soil environment for the roots and give you a greener healthier lawn.
11. Overseed in fall.  In the fall put down some seed after mowing.  The new seed will fill in some bare spots and give you new grass plants.