How to write a good essay?

How to write a good essay?
I’m horrible at writing essays. We did this thing in class were my teacher gave a student someone else’s paper, and I knew who got mine an I heard what he said about it. And it wasn’t good. So how can I be a better writer?

When i write stories, i always think of my topic. Let’s just say the beach. So i would write down some sentences that i like, that would add good detail. I then, write a gripping first paragraph, using at least one sentence that i wrote the same thing for every paragraph. Hope i helped.
Here’s a story someone used that technique for.
Gulf Shores 2010, The Great Sand Tsunami
I wiped the beads of sweat off my fore head. I was constructing a master piece. A beautiful creation, almost like an expensive piece of sculpture, crafted by Leonardo Davinci. Just now hitting the 3 hour mark, there was much to be done. We still had to shape it, pat it down, and let it dry. We had to finish soon, before the sun sets in the west, as that is the deal we made with mother.
I wake up fairly early, around 7:45, and the light from the sun is just now breathing in through the windows. I go across the hall to wake up my older cousin. We ate a light breakfast,and got dressed. Me and Brittney head across the street for the beach. It takes us literally, 47 seconds to get there, as our house is directly across the street from it. We plopped down all of our rakes and shovels, while capturing the beauty of the sugar white sand, and the sound of the blue-green waves, as they are breaking to the surface. It’s a bit distracting if you ask me. We had this plan to build a hangout area, in the sand. A little dug in part, the shape of a circle, with booth type seats that are rubbed down and made of, you guessed it, sand, and a small circular table in the middle of it all. I would dig, and she would make the seats, and we’d switch after lunch. We got started, and the sand was actually real easy to work with not too gritty, and not too wet and squishy, just the right texture for our sculpting needs. After about 3 hours of blood, sweat, and tears, but mostly sweat, we went in for lunch, and enjoyed the air conditioning as we ate.
After filling our stomachs, we head back to he beach. We were done digging by now, so we just patted down the sand in the booth seats, and made a foot rest and table, also cleaning up the edges of things and what not.
We finished just before the sun was setting on the horizon. We were walking over to go sit in it, but we were told to come home before it got dark, and we could’nt really argue with my mom, so we quickly crossed the street.
As soon as we wake up, Brittney and I rush to the beach. We gasp when we see what happened. I could hear the cracking and breaking of my heart, being shattered like when you drop a glass. The shelf/hangout center we had made was gone. Completely obliterated. There were just chunks of it laying around, like a sand tsunami had swept through, destroying whatever is in it’s path, leaving nothing behind but the small remains of what was. I think, the worst part of the whole thing, was not even getting to enjoy it. How would you feel if you spent a day on something like that, waiting to come back the next day to enjoy it, and when you come back, all you have are chunks of sand? We trudge home, and throw our selves on the couch, trying to collect our thoughts. We had just witnessed the aftermath of the great sand tsunami of 2010.