I think mixing needs to be faster - there needs to be a greater incentive to provide liquidity for mixing. It was suggested in the past that a budget proposal could be put forward to provide mixing liquidity, but as far as I know at the moment it would be a trusted solution, so the suggestion in the past was for trusted community members to offer the service, which I think is a reasonable idea if there has to be trust.
Let's say a masternode currently earns 0.63 DASH per day (according to
http://178.254.18.153/~pub/Darkcoin/masternode_payments_stats.html), on average there are about 30.4 days per month, which would be 19.152 DASH earned per month in a masternode. I don't know what would be the best amount for a liquidity provider, but I have had a little trouble mixing 100s at times in the past, so let's say 2 x 500 DASH liquidity nodes. Obviously you would need to offer a greater incentive than that which is offered to run the Masternodes with funds in a cold wallet, so let's say instead of the estimated 19.152 for 1000 DASH for one month, 40 DASH is offered as compensation - 20 DASH for each 500 DASH liquidity provider. It's not an ideal solution, because trust is involved (one entity running both liquidity nodes would not be a good idea in my opinion), but it would be one way of increasing the speed of the mixing process.
Perhaps 20 DASH wouldn't be enough though, for the risk involved. The great thing is, even if it starts out at 50 DASH per node and people agree to it, in the future someone could beat the price, so the funds could be reallocated to the new party with the better offer.