They may be lovely people, willing to help out or known for being hard-workers, but that doesn't mean they'll always live up to their promises. Then there are those who like to take others for a ride - the Mr or Ms Know-It-All's who manage to convince us that they're up to doing a task, when really all they want is our hard-earned cash!
Problems arise, however, when their screw ups really mess with our lives and, thanks to social networks, people can now share their experiences in a bid to warn us in advance!
From terrible repairs to marketing or production line fails, we've drawn up a fresh list of astonishing examples...
1. Next time get a pro and not your 'DIY' fanatic friend
2. Wonder what Wills and Meghan would think of this?
3. So what are we supposed to do?
4. Superhero fail!
5. "Make it so..."
6. American flag, Chinese production
7. When your eggs look like a rabbit on acid...
8. Leak guaranteed
9. How to destroy art
10. Factory fail
11. Just turn it upside down...
12. Never rely on labels!