Latkes are composed of potatoes, onions, matzo meal (in a pinch, bread crumbs), eggs, and salt. You can make a potato pancake with fewer or different ingredients, but it is not a latke.

Latkes are shallow fried, ideally in poultry fat (although this affects other aspects of the menu if you keep kosher). They are not deep-fried
(as in most restaurants) and definitely not baked.

People have different opinions about whether they should be very thin and crispy all the way through or have a soft interior. I think about 1" thick is ideal, but I do not insist on this.

The result should be hot, golden-brown, crispy, savory, and only slightly greasy. But what we usually get is a half-cooked or burnt grey mess.

Why does this happen? A common problem is that the grated or shredded potatoes are not sufficiently drained. You need to squeeze as much liquid as possible. Like really a lot. Otherwise, the potatoes will retain too much moisture and steam rather than fry.

But don't throw away the potato liquid. It contains starch, which helps bind the latke. Instead, drain into a bowl and let the liquid sit for until the water and the starch separate. Only then pour off the water, adding the starch back to the potatoes.

Another common problem is blandness. This can happen when do didn't use enough onions. You need a lot of onions! But unlike the potatoes, which should be shredded and aggressively drained, the onions should be left in medium dice. Otherwise they will burn.

Now, let's consider binders. We've already talked about the potato starch. In addition you need matzo meal or breadcrumbs and eggs (1 egg per pound of potatoes works for me). Do not use flour, which doesn't taste bad but does create a cakey texture. You want lacy crispy shreds.

Potatoes, eggs, matzo meal are pretty bland by themselves. They need salt. Add plenty of salt. But remember that once salt goes in, it can't come out. So add it in stages and fry a small amount of the mixture at each stage to confirm proper seasoning.

Which leads to the matter of frying. A cast iron skillet is best for this because it retains heat. That's important for keeping up the temperature of the oil when you add the latkes. If it goes down too much, soggy latkes. Bad!

The best frying medium is poultry schmaltz. Chicken, duck, goose, whatever. This makes latkes a meat dish, which may be inconvenient for various reasons. If that's a problem, you can use neutral vegetable oil with a high smoke point. But the result won't be as good.

Clarified butter is delicious but who has clarified butter lying around? Also it is not a latke. Unclarified butter will burn.