Derek Humphrey in Final Exit suggests diluting this taste by using 4 packets of artificial sweetener in fruit juice (amount not given). In the Guide to a Self-Chosen and Humane Death, peach or apricot nectar is suggested. I've also read of 2 individual cases that both used apple juice (half a bottle but amount was unspecified). In the literature, there are hundreds of cases where no mixer is used, perhaps just alcohol or chocolate afterwards, like suggested in the PPeH. I was personally thinking maple syrup could work well but I haven't decided yet.
There's lots of different suggestions but I think the theme here is similar in everything I've read... Something sugary and super sweet will help make it slightly easier. Before, During or After. It will NOT be easy, but nothing about dying is easy. What you choose just comes down to your personal preference I think.