One of the most commonly used conventions by tournament players these days is the Negative Double. These usually show values in the other suits after your right hand opponent makes a bid. How many values needs partnership agreement of course but what I suggest is 6+ hcp if the double could be made at the one level and you can rebid at the one level. eg 1♣ (1♥) Dbl (Pass) 1♠. If the double needs to be made so that you have to bid at the at the two level then it needs 8+ hcp. eg 1d♦ (2♥) Dbl (Pass) 2♠. Stick to these values and you will not go far wrong.
Todays hand demonstrates this. Played on a quiet club night with just 6 tables, after 3 passes the auction proceeded 1♣, (2♠) Dbl (4♠)... What next? You hold the hand shown:
A very nice 17hcp. So where are partners 8+hcp? He has no points in clubs because you have them all. Both opponents have jump bid in spades so he reckons not to have any points in spades either. An added "negative inference" can also be made because partner did not bid 3♠ asking for help to make 3NT. So all his points are in the red suits. He must have either AKQ♥, or AK♥, AQ♥, KQ♥ or A♥ along with K♦ and maybe J♦ its a simple game. At absolute worst the club slam is on a finesse (baring a 5-0 Club break offside of course). Just bid 6♣!
Click "Show All Hands" to view the full deal. When dummy goes down how do you play the hand? Answer, put your hand on the table and say "Drawing trumps, and playing it sensibly. One heart goes away on the fourth diamond. One goes on the ace of hearts and I give up a heart trick at trick 13."
We were the only pair to bid 6♣. Note that 6♠ would cost -500 so too much against people who are not bidding their slam.
P.S. If you managed to bid to the COLD 7♦ on this hand, I would get a new passport if I were you and claim Italian nationality, Professional Bridge Player as my profession and send a CV to someone asking to be considered for the next World Championships.