I've never really liked the idea of asking for personal things when praying. I feel it's kind of selfish to ask for personal problems when there are people in the world in much worse situations. What I think while praying (besides thanking and praising G-d) is that I give Him my tefilah and he knows better where (or when) to use it.
I never saw this as a bad thing, but I once read that some rabbi said that: "a prayer that doesn't ask for a different thing each day isn't valid". And in this answer I found, it says:
Rebbe Nachman of Breslov has many specific teachings on prayer [...] one should pray for any physical thing one needs, even something as insignificant as a missing button on one's coat.
I really don't feel comfortable when asking G-d for personal things. I believe that if I'm sick, if lost something or if anything bad happened to me, it happened because I deserved it. If G-d is completely righteous and fair, how could I tell Him that I deserve more? Shouldn't I just accept what G-d gives me without asking for more?