/diy/ - Do It Yourself

If you can get the back of the blade of a butter knife in there, holding it tightly in the screw's slot with the thumb and index of one hand, and push at the end of the handle with the other, you should have enough leverage to turn it a 1/16 of a turn, and then it will be loose.
-t. Guy who's too lazy when fixing stuff near or in the kitchen to go fetch tools downstairs.

Also watch this video:
[The ABCs of hand tools]
In this 1945 Disney cartoon we learn about Primitive Pete, Disney's imagined inventor of the hammer. The film was made for mechanics in the Armed Forces, who, like Primitive Pete, might not employ the proper technique with their hand tools—hammers, pliers, wrenches, saws, and so on. So here's 30 minutes of detailed instructions (for the most part, actually very practical and useful) on how to use hand tools. Don't be a Primitive Pete! Learn about hand tools! Don't abuse the peen end of a hammer! Be a civilized human, for a change! (Brought to you by General Motors.)

https://www.youtube.com/watch?v=fGkOOtd3GmY

Seven minutes in. There is a better design of flathead screwdriver that doesn't cam out.
Basically the tip is a bit wider right towards the end instead of narrowing all the way.