A treatment that is popular with many is the WJO. I dislike it. Sure the WJO has its moments, but I've seen so many bad ones that I believe it to be a big anti-percentage action.
It gives away too much information to the opponents in a situation when it's unlikely to be your board. It's premptive, but not enough for the advantages to outweigh the disadvantages. For instance, if you push them into 3NT they're likely to make it because declarer can hold up etc. It's of course also a matter of the opposition playing strength; weaker opps may not be able to take advantage of the WJO's drawbacks. As usual, choose your poison, but do it by choice and not habit. For me, I have better uses for the 2-level.
Last weekend, another WJO came my way. All white (pairs) and I opened 1D (11-16 unbal 4+D) with Qx/Kx/AQT9xx/KJ9 as dealer. LHO overcalled 2H and after partner's take-out X, I jumped to 3NT. West, an old buddy of mine and a decent player, led a low H.
East played the J and I won. It's easy now to fall prey to the gut reaction of leading the Q of spades. Pause for reflection and you realize that few would make a WJO with A+AQ vs an unpassed partner. The K of diamonds is a distinct possibility however and I continued H to set up an extra heart trick first. West could have saved the defence by shifting to a spade immediately but this was hard to find. He cleared hearts and I set up spades for 10 tricks and 100% on the board when the K of diamonds indeed was offside.
And another WJO bit the dust.