The most common and most likely answer to this crossword clue is the 8 letter word GIMMICKS
I've seen this crossword clue in The Daily Telegraph
G
I
M
M
I
C
K
S
Buddy explains!

The straight part
We know that "Schemes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case schemes = gimmicks.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GIMMICKS mean?
GIMMICKS noun- A trick or device used to attain some end.
- A clever ploy or strategy.
- A gimmick capacitor.
- A night out with one's friends.
- To rig or set up with a trick or device.