Start with a few good designs:
Make a new permutation for 2. You don't know which one you like best.
Update the design for 1. Also, you don't like 5, throw it out.
Use the best attributes of 3 and 4 to make a new design. Also make a new alien.
You could combine the attributes of both 2s to make a new alien, but the original permutations still look good. What do you do?
3 and 4 would work on their own if they were updated, but the combination is still cool
Make a new alien. It's also a throwback to the old number 5 in some ways.
Make a new alien. It has the same body structure as 6, but you changed the phylum.
Wait, was that a : instead of a / back there? Neat!
And so on and so forth.