Look at their feet while attacking instead of their eyes. Don’t try to shoot them with a bow and arrow; they’ll just teleport away.
Take a bucket of lava to kill the silverfish. A flint and steel will also work.
You can also scout out the situation beforehand and only take minimal armor and tools to get knowledge of the situation you’ll be in. Kill yourself after and return to the end portal. Once you get in the End, you can only get out by killing the Ender dragon or dying.
Headshots deal the most damage.
