Possibly blast a rock (6)

(Source: London Evening Standard)

"Possibly blast a" ⇒ an anagram of "blast a"

General meaning ⇒ a rock

Answer ⇒ basalt

They can help make a muddy estuary a bit colourful! (4)

(Source: London Evening Standard)

General meaning ⇒ something that makes things colourful

"muddy estuary a bit" ⇒ a subset of "muddy estuary" ⇒ e.g. "muddy estuary"

Answer ⇒ dyes

Traveller not going back to school at Derby (6)

(Source: London Evening Standard)

General meaning ⇒ a school in Derby, or Derbyshire

"traveller" ⇒ a representative ⇒ usually shortened to "rep"

"not going back" ⇒ "not" reversed ⇒ "ton"

Answer ⇒ Repton [more info]

District water suppliers? (5)

(Source: London Evening Standard)

A straightforward clue:

"water suppliers" ⇒ simply, something that supplies water

"District" ⇒ as in the Lake District (Cumbria, UK)

Answer ⇒ lakes

Dread the first slip-up (6)

(Source: The Guardian)

General meaning ⇒ dread

"the first" ⇒ the first letter of "the" ⇒ "t"

"slip up" ⇒ another word for a mistake ⇒ e.g. "error"

Answer ⇒ terror

He has both love and money in poor accommodation (4)

(Source: London Evening Standard)

General meaning ⇒ poor accommodation

"he" ⇒ here, simply the letters "he"

"love" ⇒ the tennis score? ⇒ zero points, hence "o"

"money" ⇒ given the source, the British Pound ⇒ £, a stylised L ⇒ "l"

Put it all together ⇒ "he" has "o" and "l"

Answer ⇒ hole

Household in which people grow old (6)

(Source: London Evening Standard)

"people" ⇒ e.g. "men"

"grow old" ⇒ i.e. to "age"

General meaning ⇒ a type of household

Answer ⇒ menage

Length of a coffee table? (4)

(Source: London Evening Standard)

General meaning ⇒ a length, or a unit of distance measurement

"of a coffee table" ⇒ subset of "a coffee table" ⇒ e.g. "a coffee table"

Answer ⇒ feet

Animal arrived at the first lamppost (5)

(Source: Metro.co.uk)

General meaning ⇒ an animal

"arrived" ⇒ a synonym for "arrived"? ⇒ "came"

"first lamppost" ⇒ the first letter of "lamppost" ⇒ "l"

Answer ⇒ camel

The way Poles are about to be shown (3)

(Source: London Evening Standard)

"Poles" ⇒ Polish people, but also the ends of a magnet? ⇒ here, North and South ⇒ "n" and "s"

"about to be shown" ⇒ letters surrounding "shown" ⇒ the "poles" above are at either ends of the word "shown"

General meaning ⇒ "the way"

Answer ⇒ how

He's lordly in a real way (4)

(Source: London Evening Standard)

General meaning ⇒ "he's lordly"? ⇒ i.e. a male peer

"a real way" ⇒ an anagram of "real" ⇒ e.g. "earl"

Answer ⇒ earl

Do a shifty job in poor illumination (9)

(Source: London Evening Standard)

General meaning ⇒ a form of dim illumination

"a shifty job" ⇒ implies something furtive ⇒ an undeclared second job?

Answer ⇒ moonlight

Half-safe ways can be expensive (4)

(Source: London Evening Standard)

General meaning ⇒ something that can be expensive

"Half-safe" ⇒ half of the word "safe" ⇒ i.e. "fe"

"ways" ⇒ directions? ⇒ points of the compass ⇒ e.g. East and South ⇒ "es"

Answer ⇒ fees

Saloon at the Nag's Head possibly used for a dance (4)

(Source: London Evening Standard)

General meaning ⇒ somewhere or something that can be used for a dance

"saloon" ⇒ another word for a saloon? ⇒ e.g. a "bar"

"the Nag's head" ⇒ the head of "Nag's" ⇒ the letter "n"

Answer ⇒ barn

Tendency for a doctor to be unusually fit (5)

(Source: London Evening Standard)

General meaning ⇒ tendency

"a doctor" ⇒ shortened form? ⇒ Dr, hence "dr"

"unusually fit" ⇒ an anagram of "fit" ⇒ e.g. "ift"

Answer ⇒ drift

Being sly about me getting money is distinctly fishy! (6)

(Source: London Evening Standard)

"sly about" ⇒ the letters of "sly" surrounding something

"me getting money" ⇒ the letters "me" getting (added to) "money" ⇒ Given the source, money is the British Pound ⇒ symbol for the British Pound? ⇒ "£" ⇒ which is a stylised "L" ⇒ so "mel"

General meaning ⇒ something that is "distinctly fishy"

Put it all together, you get:

Answer ⇒ smelly

Move to a lower station (8)

(Source: London Evening Standard)

"Move to a lower" ⇒ anagram of "to a lower"

General meaning ⇒ the name of a station ⇒ Given the source, a station in London?

Answer ⇒ Waterloo

Made sure of five out of seven (4)

(Source: London Evening Standard)

General meaning ⇒ "made sure of"

"five" ⇒ in Roman numerals? ⇒ "v"

"out of seven" ⇒ the preceding taken away from "seven"

Answer ⇒ seen

It's the stone in a ring, mate (4)

(Source: London Evening Standard)

"a ring mate" ⇒ consider as "a ring" plus "mate"

General meaning ⇒ it's "the stone" ⇒ word for or name of a stone ⇒ a gemstone?

"a ring" ⇒ the shape of a ring? ⇒ i.e. the letter "o"

"mate" ⇒ another word for "mate" ⇒ e.g. "pal"

Answer ⇒ opal

Stealth is one of the last (7)

(Source: The Guardian)

"stealth" is one of "the last" ⇒ note that "stealth" and "the last" have the same letters ⇒ so what is "stealth" one of?

Answer ⇒ anagram

I'm in business to make a speech (6)

(Source: London Evening Standard)

"I'm in" ⇒ "I" am in ⇒ i.e. the letter "i" inserted into...

"business" ⇒ another word for business? ⇒ e.g. "trade"

General meaning ⇒ a speech

Answer ⇒ tirade

Italian centre of barbarians (4)

(Source: London Evening Standard)

General meaning ⇒ relates to Italy ⇒ an Italian city or region?

"centre of barbarians" ⇒ middle letters of "barbarians" ⇒ e.g. "barbarians"

Answer ⇒ Bari

Water in moderation (4)

(Source: London Evening Standard)

General meaning ⇒ relates to water ⇒ name of a lake, river, sea etc?

"in moderation" ⇒ subset of the letters of "moderation" ⇒ e.g. "moderation"

Answer ⇒ Oder

Do other birds retreat from this one? (4)

(Source: London Evening Standard)

General meaning ⇒ Name of a bird ⇒ a predator ⇒ found in the same environment as the "other" birds?

"retreat" ⇒ reverse the letters in the answer to get the "other" birds

"other birds" ⇒ collective noun or plural of a type of bird ⇒ e.g. "auks"

Answer ⇒ skua

The immortal love racket (4)

(Source: London Evening Standard)

"love" ⇒ as a tennis score? ⇒ zero ⇒ thus "o"

"racket" ⇒ a loud noise ⇒ e.g. a "din"

General meaning ⇒ "The immortal" ⇒ a god

Answer ⇒ Odin

Discomfit seaman Wood (5)

(Source: London Evening Standard)

General meaning ⇒ "Discomfit"

"seaman" ⇒ e.g. the Royal Navy rank "Able Seaman" ⇒ abbreviated "ab"

"Wood" ⇒ a type of tree? ⇒ e.g. "ash"

Answer ⇒ abash

Remember about a visit (6)

(Source: London Evening Standard)

General meaning ⇒ "Remember"

"about" ⇒ i.e. regarding ⇒ also "re"

"a visit" ⇒ another word for "visit"? ⇒ e.g. "call"

Answer ⇒ recall

One thousand and nine in the assortment (3)

(Source: Metro.co.uk)

General meaning ⇒ assortment

"one thousand" ⇒ Roman numerals? ⇒ M, hence "m"

"nine" ⇒ Roman numerals? ⇒ IX, hence "ix"

Answer ⇒ mix

Beastly blenders of wines (5)

(Source: London Evening Standard)

General meaning ⇒ beastly ⇒ some kind of (or word for) animal

"Blenders of wines" ⇒ anagram of "wines"

Answer ⇒ swine

Illustrations made with starch (6)

(Source: London Evening Standard)

General meaning ⇒ plural form of some kind of illustration

"Made with starch" ⇒ anagram of "starch"

Answer ⇒ charts