Some might have already heard this from others. But it's good to remember.
While listening to a certain lecture online, the speaker made a good point about why we count up during sefiras haomer and not down. I would have mentioned this message back then, but I only recently watched it. Anyway, he said that we count up and not down because when you count down, those days in between are in the way, and it feels like a long time until you reach that special day. However, during the omer, each day counts, and we are suppose to use each day as a chance to grow. We count up, taking one step, and then two steps and three. On the 48th day we are 48 steps closer toward Shavous.
It's like a student waiting to graduate. They can either count down the days until they're done with school, and feel anxious, and just want to fast forward to that day. Or they can take the opportunity to use this time wisely as they come closer to that day.