Probably the most important factors of lawn care are mowing height and frequency. Fertilizer aside, more importantly - you will want the grass in your yard to be a certain height to ensure not only its pleasing appearance, but its health, and you will also want to actively maintain this height.
First of all, people sometimes aim to cut their lawn as short as possible. But in actuality, as long as your lawn is even and not especially tall, it won't look unkempt or overwhelming if it's a little long. Because of this, it's best to keep your grass at a healthy height. This is because a thin, short lawn with shallow roots is vulnerable to pests and can't be fertilized easily. However, you don't want your lawn to grow too tall, as that can be unattractive, difficult to mow, and of course you'll encourage pesky weeds to sprout up.
So what height is best for your lawn? It depends on the species of grass you're dealing with and the season, as grass grows at different rates as temperature and rainfall changes. Basically, a good mowing height for spring and fall is at least 2 inches. As for those hot summers, 2.5 inches is an appropriate height.
Now, you must keep on top of things. But there is no set schedule for mowing your lawn, as you will simply have to adapt to however fast or slow your grass grows. The rule of thumb is that you should never remove more than a third of the length of the grass blades when mowing. In other words, don't cut down your lawn to a healthy 2 inches until it's grown to about 3. Sometimes you'll have to mow a lot; other times, not so much.
By maintaining your lawn, you can also mulch it. It's hard to mulch your lawn if you let it get too wild because that will only promote overgrowth and untidiness. So in order to keep your soil rich in nutrients, make sure to mulch your lawn routinely. Some wetter seasons may require you to bag it, however.
Hopefully, now you have an idea of what mowing height and mowing frequency is right for your lawn so you can promote a lawn that's thrives and looks good.