A solve of fits and starts and a minute over target at 11 minutes. I'm not sure that's a good reflection of difficulty here as I was rushing in between other things or maybe it was the double definition count (I counted half a dozen). Thanks to Mara (who gets a mention in an anagram) - I enjoyed writing this one up.
1. Girl created sounds (4)
MAID - homophone (sounds) of created - made.
after at joker, jack , queen or king (4,4)
FACE CARD - look at (FACE) after which is joker (CARD).
8. Bring up figure in cooped up animal? (8)
HEIGHTEN - figure (EIGHT)
cooped up inside coped up animal (HEN).
9. Spy contract (4)
BOND - double definition.
10. Sound the horn going forward and reversing (4)
TOOT - palindrome.
11. Real flat bombs, essentially (5,3)
AFTER ALL - anagram (bombs) of REAL FLAT.
12. Story about harbour (6)
REPORT - about (RE), harbour (PORT).
14. Pluck something from the wine cellar (6)
BOTTLE - COD to this double definition for the surface and how long it took me to get the first - pluck as in heart/grit/bottle.
16. During flight, loin cut in half - piece of meat (8)
ESCALOPE - inside flight (ESCAPE) is (LO)in - half cut.
18. Part of Cairo, metropolitan capital (4)
ROME - part of Cai(RO ME)tropolitan.
19. I appreciate that team one's hailed (4)
TAXI - I appreciate that (TA), team (XI).
20. First of colonists in Armenia moving from Georgia, say? (8)
AMERICAN - (C)olonists inside an anagram (moving) of ARMENIA.
22. Big celebrity gets Mara excited (8)
MEGASTAR - anagram (excited) of GETS MARA - name dropper!
23. Tidy way to serve whisky? (4)
NEAT - double definition. Another drink related one.
2. Individual after different name for plant (7)
ANEMONE - individual (ONE) after an anagram (different) of NAME.
3. Number enjoy computer technology (5)
DIGIT - enjoy (DIG), computer technology (IT).
4. Suitable attack (3)
FIT - another double definition.
5. One who had a brush with the law? (9)
CONSTABLE - yet another double definition and I think this pips 14ac for COD. Great surface and the first definition is the artist.
6. Plain circled by lion, perhaps, for entertainment (7)
CABARET - lion, perhaps was obviously (CAT) but what it was circling took a while - plain (BARE).
7. Learn to play on an organ (5)
RENAL - anagram (to play) of LEARN. Not sure about this one - if it was 'of an organ' then OK but it's on an organ - so the definition is the organ which is the kidney - renal describes things that concern or are related to the kidneys. Does 'on an organ' work as renal? [on edit - the answer is yes - please see jackkt's comment below].
11. A confident walk catching on with a spaceman (9)
ASTRONAUT - a confident walk (A STRUT) catching on with a (ON + A).
13. Air-con adjusted with a rare instrument (7)
OCARINA - anagram (adjusted) of AIR CON. Even if you don't know this, there didn't seem too many ways of filling the answer in wrongly - but what do I know? Let me know if this caused problems.
15. Greek character hosting a dance (7)
LAMBADA - Greek character (LAMBDA) hosting a (A).
17. Extra frugal (5)
SPARE - LOI to the last and tricky double definition. Extra as in over/frugal as in meagre, sparing, modest, plain.
18. For the auditor, check rule (5)
REIGN - homophone (for the auditor) of check - rein.
21. Installed in house, a reed organ (3)
EAR - inside (installed in) hous(E A R)eed. No quibbles with this organ.