First of all I'm no expert and I've read the same thing about ID'ing certain Meadowhawks, it's tricky to say the least and often impossible without close examination.
So, after checking my field guides;
1. White-faced Meadowhawk, male - white face, black legs, no amber patch at base of wings.
2. Ruby Meadowhawk, red female - Ruby due to black legs, tan face, black veins on leading edge of wing, amber patch at base of wings. Red female due to red above, yellow below on abdomen and eyes reddish-brown over pale green.
3. Variegated Meadowhawk, male - face red, black legs with yellow lengthwise stripes and complex rather than the typical, red/black patterned abdomen.