For the most part when breeding cresteds you will get a combination of these results:
1. offspring that look like the male
2. offspring that look like the female
3. offspring that look like a combination of the male and the female
4. offspring that look nothing like the male or the female (possibly that look like the grandparents of the male or female or are a result of other non-visual genetics)

Generally speaking the first two results are most common, the third the next most common and the fourth the least common, however nothing is set in stone and you could wind up with anything. You will notice certain tendencies, like browns tend to take precedence over reds and oranges, therefore if you have one red crested and want to produce more you should choose another red gecko as the mate as opposed to anything brown.

What you choose as the mate for your geckos depends entirely upon what you want the result to be. Choose something that you want to make more of and something that you would like to see in combination with what you will be breeding it to. Some combinations are harder to make than others, such as red harlies and creamsicles, so if you wanted to use your females for a red harley project your very best bet would be to get a red harley male, but you can always choose any color male with cream patterning and hope for offspring that get his cream and the female's red (but again there is no guarantee that that will actually happen and it also depends on the genetics of the geckos you are using for the project).