Shrimp will sear nicely if you know how to handle them! It’s incredibly important to start with an already hot pan. Turn the stove to medium-high or high and let the empty pan heat for a few minutes. To test the pan temperature, drop a bit of water into it. It should sizzle and dance/ bounce on the surface.
Drop a pat of butter into the pan- it should sizzle and melt incredibly quickly. Move it around in the pan so the bottom is coated. If you briefly sizzle butter in an empty pan, it will start to brown on its own, which will add a nice color and flavor to the shrimp. Not too much, or the butter will burn.
Have the shrimp ready and waiting next to the stove, and add them when the butter is just right. (Having them dredged with flour or spices beforehand can’t hurt.) They should cook incredibly quickly, maybe in under a minute. Move them around the pan so they don’t stick or burn, and take them off the heat the second they’re finished.
Shrimp are one of the fastest-cooking foods, so in a dish with multiple steps/ ingredients, I usually make them last.