Across
Side of Paris lacking in sophistication (6)
I haven't cracked this one yet — but Fifteensquared have:
Double definition – though the two aren’t really separate definitions. Gauche is French for “left” (as opposed to right) = one side in Paris; but “gauche” meaning clumsy or unsophisticated seems to originate from the same word, as part of a long-standing prejudice against left-handers. (In many languages, “right” is more or less the same word as “correct” or “straight”, but “left” tends to have negative connotations; as well as “gauche” there’s the Latin “sinister”.)
Secure position, for example, protects fleet regularly (6)
I haven't cracked this one yet — but Fifteensquared have:
SAY (for example), around (protecting) alternate letters (regularly) of F [l] E [e] T .
Part of River Island's ... (4)
I haven't cracked this one yet — but Fifteensquared have:
IS IS = two of IS, short for island. Of course apostrophe-S doesn’t normally indicate a plural, but sometimes it’s used for plurals of abbreviations; or you could just say we should follow the usual crossword rule of ignoring punctuation. [UPDATE: As Hovis @3 points out, it’s one IS for “island” and another IS for the apostrophe-S = “is”.] And for the sake of the surface, “River Island” is a high-street clothing brand. Name for the upper part of the River Thames, especially where it flows through Oxford, before it joins with the River Thame to become the Thames.
... publicity found in note on back of T-shirt's label (9)
I haven't cracked this one yet — but Fifteensquared have:
AD (short for advertisement = publicity) in REMARK (note), after (on) the last letter (back) of [t-shir] T .
Rhetoric's upset member of vocal group (9)
Football players missing start of season (5)
I haven't cracked this one yet — but Fifteensquared have:
[w] INTER (a season), missing the starting letter. Short name for the Italian football club Inter Milan (officially Football Club Internazionale Milano). Or perhaps for any one of several clubs elsewhere that have “Inter” or “International” as part of their name.
Celebrate about One Direction's first track (6)
I haven't cracked this one yet — but Fifteensquared have:
SING (celebrate), around I (one in Roman numerals) + first letter of D [irection]. The boy band One Direction are often abbreviated to 1D, but that isn’t necessary to solve the clue. Siding = a section of railway track that isn’t part of the main route.
Mixes up a horse and sheep (8)
Object when he has rules connecting words? (2,6)
I haven't cracked this one yet — but Fifteensquared have:
END (object = target) + AS (when) + HE’S (he has). En dash = a medium-width horizontal line (rule) that can be used as a connector in a sentence, for example in ranges such as “April–July”. Printing style guides can go on for hours about the “correct” usage of hyphens, en dashes and em dashes; let’s not go there.
Uncertainty about terms of EFTA causes company's failure (6)
I haven't cracked this one yet — but Fifteensquared have:
IF (uncertainty) reversed (about) + end letters (terms) of [eft] A [cause] S + CO (company).
Children announce supply problem (5)
I haven't cracked this one yet — but Fifteensquared have:
Quadruple definition. As in “deceased without issue”; as in “to issue a decree”; as in “to issue rations to . . .”; or as in “Houston, we have an issue . . . ” as they would probably have said a few decades later.
Pressure on writer to specify rules (9)
Cocktail drink with piece of cake (3,6)
Witnesses reporter's arrest (4)
I haven't cracked this one yet — but Fifteensquared have:
Homophone (reporter’s . . .) of SEIZE = arrest.
Sympathetic minister to make a proposal (6)
I haven't cracked this one yet — but Fifteensquared have:
Triple definition. Caring; someone who tends (looks after) another; or a formal offer to supply goods or services for a stated price.
Singer in time produces wrong notes (6)
Down
Sailor transferred having dropped ecstasy and gone AWOL (9)
I haven't cracked this one yet — but Fifteensquared have:
AB (short for able seaman = an experienced member of a ship’s crew) + S [e] CONDED (as in “on secondment” = transferred), without the E (short for the drug ecstasy).
Reduce the impact of Conservative Government leaving housing in a mess (7)
I haven't cracked this one yet — but Fifteensquared have:
C (Conservative) + anagram (in a mess) of HOUSIN [g] without the G (short for Government). As in “to cushion a fall”.
Property in European country (6)
I'm annoyed about cartel playing a big role (8)
I haven't cracked this one yet — but Fifteensquared have:
RATS (rats! = a mild expression of annoyance) reversed (about), then RING (cartel).
Touching love scene finally unites divided cast (7)
I haven't cracked this one yet — but Fifteensquared have:
Final letters of [lov] E [scen] E , inserted into FLING (cast = throw), and therefore uniting the divided parts of it.
Characteristic means of conveying something to some of the audience (5)
I haven't cracked this one yet — but Fifteensquared have:
Homophone, or not, depending on your pronunciation (“to some of the audience”) of TRAY (a means of conveying, or carrying, something). Personally I’d pronounce the T at the end of TRAIT, but the dictionaries accept both pronunciations, and Serpent has acknowledged that the homophone won’t work for everyone.
Solid border on some flags? (9)
I haven't cracked this one yet — but Fifteensquared have:
Cryptic definition: “flags” here are flagstones, such as might be found on a pavement, with kerbstones forming the border at the edge. Our US readers would probably call them curbstones, and they’d also find flagstones on a sidewalk instead of a pavement.
Universal Studios finally accepts film features may be enhanced by them (9)
I haven't cracked this one yet — but Fifteensquared have:
COSMIC (universal) + final letter of [studio] S , containing (accepting) ET (the Spielberg film that’s a gift to crossword setters).
Moderate state briefly confused with Benin (9)
I haven't cracked this one yet — but Fifteensquared have:
Anagram (confused) of STAT [e] (briefly = all but the last letter) with BENIN . Moderate = abstinent = not given to over-indulgence.
Come back to harvest fruit (8)
Drove home point and moved quickly to capture attention (7)
What may be biting and ironic satire's beginning to be broadcast (7)
I haven't cracked this one yet — but Fifteensquared have:
Anagram (broadcast = scattered) of IRONIC + beginning letter of S [atire]. Incisor = front tooth.
Remove what stops court action blocking incomplete legal document (6)
Small fish flourish (5)
Type letters or click words in the clue