Do you play Lebensohl?
Well, consider this one. Use a diamond advance to a passed double of a club opening as "Lebensohl," also called a "Herbert Negative."
How would this work?
Consider the simplest auction. LHO opens 1♣ and partner doubles.
This double might typically show a three-suited hand with opening strength, of course, but "three-suited" is VERY flexible. This is not remotely the Min-Roman 4-4-4-1 with a 5-4-4-0 exception. "Three-Suited" means, in practice, anything with three cards in each suit, although the "other minor" is suspect even to that degree, with possible lop-sided "equal level conversion" holdings, and maybe as strange-looking as 4-3-3-3 with four cards in Opener's suit. How about range? If you are three-suited, the range is something your partner will not shoot you for up to 40 minus whatever Opener has. But, the bid also might not resemble this definition if partner has the "almost a strong 2♣ opener," the "just about a 2NT opener," or the "ACOL-style two-bid opener" variations of the double. So, he has some amorphous interesting hand.
Back to the auction. RHO passes.
This sequence creates a silly problem. Responder might have a hand worthy of a cuebid or a jump. If not, however, his range is somewhere between about a 9-count down to a 0 count with a sick three-card least-of-all-evils suit.
Using the Herbert Negative 1♦ bid, however, we now have some structure:
1♦ = weak, bust, run for the hills
1♥ = heart suit, values (maybe 5-8 or so)
1♠ = spades, values
1NT = normal
2♣ = normal
2♦ = diamonds, with values
This way, partner knows a little more about your hand in the event that either (1) he has strength and wants to know how to proceed or (2) Opener has strength but partner wants to know how to compete.
How about after a Precision 2♣ (11-15 with clubs)?
Same principle. 2♦ is the bust hand, making 2M show "values." This allows mild game tries without leaving the comfort of the two-level.
How about 3♣-X-P? Same thing, with a 3♦ "lebensohl" or "Herbert Negative" bid. Advancer can now distinguish between "three-please-don't-double-hearts," "three-wanna-try-four hearts," and "four-really-mean-it- hearts." That's better than "three-ugly-or-promising-you-guess-hearts" and "four-maybe-you-have-my-bid-hearts."
What after the relay? After 1/2/3♦ as "Herbert," partner is expected to usually bid 1/2/3♥ to allow you to pass/correct at the right spot. This forces us up one level when the contract should be a low-level diamond contract, but that loss is met by many gains.
A tweak might be for an immediate jump to diamonds (e.g., 1♣-X-P-2♦) to be weak, such that the non-jump (e.g., 1♣-X-P-1♦) shows either a weak hand OR a hand with promise and diamonds. Or, you might treat an immediate 1NT as a positive with diamonds and a delayed 1NT (through 1♦) as a positive without a suit. There are some merits to these treatments -- I'll leave anyone interested to decide.