Going out to look mix and mingle with potential dates is always more fun with friends, but it can be a big decision when choosing an outfit. Match the crowd is generally a good idea, but influencing them might be a better one. If everyone is determined to dress to the hilt, there is no chance of displaying personal clothing habits. A person looking for someone less than the most successful and career oriented person at an event will find they are less likely to end up with anyone at all.
Being able to relax in social situations is important, and it can help the conversation flow when meeting new people. Those who are too aware of their outfit or appearance will often find their conversation becomes stilted as they worry about how they are being perceived. Avoiding this might not be possible in some groups, but suggesting a more casual appearance before an event could bring about a bit of chance. If only one person is continually meeting dates while everyone else is high and dry, it could be a welcome suggestion for the entire group.