[kgr]

Unexptedly we played champion in our (..not too high) range. We play a rather special system (like 1NT overcall is not 15-17, but for the minors; and a lot of transfer bids & two-suited overcalls). But my feeling is that Obvious switch is the part of our system that was most usefull (beside the excellent advice I received on these forums ).
Obvious switch:
On your partners opening lead in a suit you don't signal if you like that suit or not, but a low card says that you like the obvious switch suit (you have a set of pre-arranged rules that determines the obvious switch).
If you couldn't signal on the opening lead (e.g you had to play high) then you play lavinthal on the next trick(s) to signal the suit you want.

[kfay]

I play obvious shift with a normal partner of mine. I like it, I think.

Here's a recent hand that came up playing OS.

Scoring: MP

(P)-P-(1♦)-1NT
(2♥)-P-(3♦)-All Pass

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You lead the ♣A. Partner plays the 10, declarer plays the 8.

You play UDCA

Don't ask about the bidding...