Man has most of the time prayed for the very wrong things that he wants; not realizing of the things that he truly need is very far different. This is why he never gets what he prays when to God. The clothes in this context refers not just to clothes, but also to other materials.
MT 6:28 "And why do you worry about clothes? See how the lilies of the field grow. They do not labor or spin. 29 Yet I tell you that not even Solomon in all his splendor was dressed like one of these. 30 If that is how God clothes the grass of the field, which is here today and tomorrow is thrown into the fire, will he not much more clothe you, O you of little faith? 31 So do not worry, saying, `What shall we eat?' or `What shall we drink?' or `What shall we wear?' 32 For the pagans run after all these things, and your heavenly Father knows that you need them. 33 But seek first his kingdom and his righteousness, and all these things will be given to you as well. 34 Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own.
MT 6:5 "And when you pray, do not be like the hypocrites, for they love to pray standing in the synagogues and on the street corners to be seen by men. I tell you the truth, they have received their reward in full. 6 But when you pray, go into your room, close the door and pray to your Father, who is unseen. Then your Father, who sees what is done in secret, will reward you. 7 And when you pray, do not keep on babbling like pagans, for they think they will be heard because of their many words. 8 Do not be like them, for your Father knows what you need before you ask him.
To pray is to be able to perceive differently for this is the Truth you will receive.