I always try to be neat and clean, because I never know who I might meet, and first impressions do count-- much more than you might think.  Mentally, you will also look and feel better when you are at your best and it shows.

This bit of advice is even more important when you might want to let yourself go a bit.  When you have lost a job, gotten divorced, or a relationship just ended.  The next person you meet or the old acquaintance you run into may be the one who leads you to your next job or significant other.  Your next client could be right around the corner.

By neat and clean, I don't mean spending boatloads of money on wardrobe.  What I do mean is combed or brushed hair, a recent shower, a clean shave or trimmed beard, and clothes that look and smell fresh-- not like they just came out of the hamper.  If you have to wear a uniform, for me that is often a suit and tie, be sure it is clean and pressed.

While it shouldn't be true, it is true-- people judge books (you) by their covers (appearance).  Your job, your relationships, and your wallet can all be impacted by it.

Make the right first impression!