Across:
1 Tries on clothes (MODELS) in various styles (MODELS),
4 Freely (= anagram indicator) use cadet (use cadet = EDUCATES) schools (EDUCATES),
9 Hesitantly drops this (‘hesitantly’ drops ‘this’ = etanly = NEATLY) in an orderly fashion (NEATLY),
10 Seed (GERM-) doesn’t cost anything (-FREE) (GERM-FREE) – as a result someone must have really cleaned-up earlier on? (GERM-FREE),
12 Driver’s (drivers = GOLF CLUBS) car (GOLF) association (CLUB-) and school (-S) (GOLF CLUBS),
13 Seasonal work (CYCLE) for the pedlars (pedlars) in a manner of speaking (= homophone indicator) (for the ‘pedlars’ = for the ‘pedallers’ = CYCLE),
14 Individual (-ONE-) accommodated in my (M-Y) conversion (CHANGE-) is finding resistance (-R) (MONEY CHANGER) from one of those exchanging notes for the coppers (MONEY CHANGER),
18 One of The Baskervilles (Baskerville typeface/font = F-ONT) admits writing (from the 3Rs = -R-) to The Messenger’s (messengers = RUNNERS) (FRONT RUNNERS) people taking the leads (FRONT RUNNERS),
21 Pressure to dismiss rep (‘pressure’ to dismiss ‘rep’ = ssure = USERS) for consumers (USERS),
22 Familiar (STOCK-) extremes of horror film (extremes of ‘HOrror fiLM’= -HOLM) (STOCKHOLM) found in 8 down (STOCKHOLM found in ‘Sweden’),
24 Small (S-) debts (IOUs = -IOUS) in the end (= positional indicator) mushroom (cep) up? (= reversal indicator) (cep = -PEC-) (SPECIOUS) That could be true but it’s not! (SPECIOUS),
25 Most of (p) the advice (‘help’ without ‘p’ = HEL-) given by forecasters (-MET Eireann) (HELMET) goes over the head of one on site (HELMET),
26 Annoys (HENPECKS) tops of nerve plexus (tops of ‘Nerve Plexus’ = -NP-) in damaged (= anagram indicator) cheeks (cheeks = HE- -ECKS) (HENPECKS),
27 It’s not clear (BLURRY) bee flew away from blueberry (‘bee’ flew away from ‘blueberry’ = lubrry = BLURRY).
Down:
1 Sage (sage/genius = MIND) and pheasant (GAME) (MIND GAME) – that’s bound to mess with your head (MIND GAME),
2 The cut-off point (DEADLINE) for Aeneid (Aeneid) adaptation (= anagram indicator) (Aeneid = DEA-INE) includes Dublin (-D-) leading lady (leading ‘Lady’ = -L-) (DEADLINE),
3 Sample of vermicelli lacks (sample of ‘vermicelLI LACks’ = LILAC) something fragrant from the olive family (LILAC),
5 Outfit (DRESS-) popular (-IN-) with one getting married (groom = -G ROOM) (DRESSING ROOM) in the abbey? (in The Abbey Theatre = DRESSING ROOM),
6 Show up (COME) drug-free (CLEAN) (COME CLEAN) – it’s what one might do in confession (COME CLEAN),
7 Article (the = TH-E) about motoring organisation (Royal Automobile Club = -RAC-) (THRACE) in old country (THRACE),
8 Resist leaving dessert wines (‘resist’ leaving ‘dessert wines’ = dewnes = SWEDEN) in the country (SWEDEN),
11 Don’t worry about losing the fortunate advantage (PUSH ONE’S LUCK), as a fair amount (half) thus (half ‘thUS’ = -US-) improves (hones = -H ONES) in spirit (pluck = P- LUCK) (PUSH ONE’S LUCK),
15 The Royals’ (The YORKS-) take on (-HIRE) (YORKSHIRE) type of puddings to go with the roast beef (YORKSHIRE puddings),
16 One making alterations to one’s character (REFORMER) in Luther, for instance (Martin Luther = 15th reformer from Reformation = REFORMER),
17 Relates to muscular tension (ISOMETRY) produced by a few (-SOME-) after (= position indicator) first (I-) score in rugby match (-TRY) (ISOMETRY),
19 It’s revolting (uprising/coup = PUTSCH) place (PUT-) for small (-S-) church (-CH) (PUTSCH),
20 Terrain off Mediterranean (‘terrain’ off ‘ Mediterranean’ = medean = DEMEAN) provides a base? (‘a base’ = ‘abase’ = DEMEAN),
23 Dead ringer (funeral bell = KNELL) for king (K-) with pretty, witty mistress (“pretty, witty” Nell Gwyn, mistress of Charles II = -NELL) (KNELL).