11 Across (three words) is a phrase suggested by the puzzle’s title explaining how to arrive at the other unclued lights, which are anagrams of words of a kind, all confirmed in Chambers (including two less common spellings).

Across

1 Beaten up coin is showing heraldic beast (8)

8 Some stuff is crammed in purse once (4)

14 Troublemaker in prison on remand to start with (7)

17 Tests principles initially found wanting (5)

18 Earl ripped up least military decorations (8)

21 Person’s tailless bird of legend (4)

22 Horse in rain gets incitement (4)

23 Amerindians holding...