The answer to each clue below is a two-word phrase. All the phrases are related in a way that involves their structures, but not their meanings.

1. Poverty-stricken
2. Too much plastic surgery
3. Mixed greens fit for a king
4. Calliope, regarding The Odyssey
5. #2 guy in the pecking order
6. Savings for future religious service
7. When this is in, it's over - even for Yogi
8. #2 heron

Answers to clues:

1. Dirt poor
2. Botox look
3. Royal salad
4. Homer's Muse
5. Second banana
6. Mission fund
7. Final score
8. Second egret 

How the clue answers are related:

HINT:
It  has to do with their beginning and ending letters.

Answers:

1. Dirt pOOR - open door
2. BOtox loOK - open book
3. ROyal salAD - open road
4. HOmer's mUSE - open house
5. SEcond bananA - open sea
6. MIssion fuND - open mind
7. FInal scoRE - open fire
8. SECond egRET - open secret

Credit:
Joseph Appel