Totally serious here. By order I would make it:
1- "After a feat, a defeat" - Seeing a big underdog player beating a big player almost always ends with a lose in the next game, ie- Kyrgios won vs Nadal and lost the next game, Coric won vs Nadal and lost the next game, Karlovic won vs Djokovic and then lost the next game, Seppi won vs Federer and then lost the next game, Tatsuma Ito won vs Wawrinka and lost the next game. Also works with after winning a title. Sometimes the odds are not that great but there is value
2- believe the odds when they are dropping. Totally makes sense 90% of the time. When I got a big lean, I usually look for a line drop, I would say 0.2 makes me even more confident for it.
3- check also at least for 2 more opinions. Sometimes you just found yourself thinking "I know he is going to win!". Well, with the time I started to try to avoid this feeling, which still happens almost everyday. Still, I now look for more opinions and look for more information. Another money saving thing.