Don't dress to look like your present situation, dress to look like your future. A lot of persons dress anyhow, thinking nobody cares about how they look. In case you do not know, the way you dress is the way you will be addressed. You cannot dress like a poor man and expect to be treated like a boss, you cannot dress like a beggar or a slave and expect to be treated like a king, it doesn't work that way.
Even if you have just one shirt and a trouser, wash them well, iron them and wear them with confidence and good self-esteem. You don't need to look sad because you do not have enough, take good care of the ones you have. You do not have to be great before you start dressing well, start dressing like your future from today.
Your dressing tells people who you are and where you are headed to. Do not dress like a failure, dress like the success that you are.