Crossword Help Forum
Forum Rules

4d, ??e????, Social networker using rather cute short name.
5d, ??t?????a??????, Change trains? One might, crossing tip of English county.
6d, ??r????, Head of organisation is in control, and that's official.
11a, ?p?o??, Develop as writer whose son's gone to the front.
21a, 2words, 5.3. Sti?? ???, Robberies on the increase among crooks.

21 stick ups

11 sprout (Proust)

twee ter(m)
Nottinghamshire, anagram
cor(o)ner

Thanks scorpiojo, think I have 5d, has Nottinghamshire.

Thanks ginge, must crossed posts.