I don't think there are any specific rules or guidelines for it but I'd say a natural muted look is probably best for a maid look. Don't go too over the top with makeup or crazy hairstyles.
(Also, that maid uniform reminds me a little of the one I'm pretty sure Mikuru wore at one point in The Meloncholy of Haruhi Suzumiya but I haven't watched it in a while and I can't quite remember...)
Future Cosplays (not working on yet):
Aradia Megido - 30%
Chihiro Fujisaki - 60%
God Tier Eridan - 50%
Asuka Langley Soryu - 90%
Monobear, Touko Fukawa, FLARP Eridan, Wonderful Cat's Life!Gumi, Emmy Altava, Shinji Ikari, Yotsuba, Toro Gijinka, Cirno, Neptune