Many people think that because they're very flawed or nothing special, then their prayers are nothing special either.
But this isn't true.
Particularly when praying for others, a sincere prayer from the heart of an otherwise flawed and sinful person can still be very powerful.
How does this work?
God is Your True Parent
And let's say that one of your children possesses the ability to be serene, caring, clean, and to courageously do the right thing, yet instead is pulled after his or her yetzer hara.
And so this same child tends to act out as a bitter, selfish, resentful, rebellious, chutzpadik brat. Furthermore, this same child also enjoys a good romp in the local pig sty, making this child often dirty and smelly.
Yet upon seeing the suffering or potential suffering of another sibling, let's say this child comes to you in all his or her muckiness and addresses you with a heartfelt plea: "Mom/Dad, I know that due to my usual behavior and appearance, I don't deserve any favors from you. However, I'm genuinely concerned about my sister. She's about to marry the wrong guy/she's not healthy/she's suffering from serious financial problems/Etc., and I can't sleep at night thinking about everything she's going through. Her pain also pains me personally. Can you please, please help her out? I really can't stand to see her suffer. Please?"
How would you feel?
Wouldn't your heart be touched that this self-absorbed wild child decided to leave his or her bewitching pursuits for a moment to care about and plead on behalf of his or her sibling?
Wouldn't you be gratified and hopeful at this wonderful sign that maybe, finally, your errant child is coming out of his or her own personal darkness?
And despite your child's stench, filthy appearance, and appalling behavior, wouldn't you feel moved to respond positively to such a heartfelt and selfless plea?
Obviously, Hashem is infinitely above human emotions. So far above, in fact, that His Love and Compassion toward us is beyond anything we can ever feel for each other, including for our own children.
And so this kind of prayer is very powerful. Therefore, you shouldn't automatically dismiss yourself as so wretched or unimportant that God won't take note of your prayers. He will!
Many people mistakenly assume that it's gaava (arrogance) to feel that their prayers are important and even transformative. But in reality, this assumption of gaava is a heretical and harmful assumption. Your prayers and your conversation with God are very precious to Him.
(Your connection with God is also the only way out of the pig sty and the soul-destroying behavior, whether your own or someone else's.)