regarding you example, almost always we use this long expression: -- cerco di fare del mio meglio Other example: Non so se vi piace il risultato, ma ho fatto del mio meglio.

"Cercare di" is "to try" when it is followed by an infinitive. For example "Cerco di spiegare" : I try to explain. Your example, "cerco il mio meglio" means "I look (search) for my best", whereas I think you wanted "I try my best". Provare is followed by "a" plus an infinitive. So "Provo a spiegare" : I try to explain. You can see that the meaning is the same, but the usage is different. I hope this helped somewhat. I'm sure someone with much more skill in Italian (ie a native speaker) will come along and give a much better explanation! :)