the "candy flip" as most call it (I prefer just saying "lsd and mdma combo") is pretty much my favorite altered state of consciousness. I have quite a bit of experience with different timings, dosages, and other factors - each which create a completely different experience than the next.
For your first, I strongly recommend dosing your lsd (always at once, never boosting), then just enjoy that for quite a while, basically put the mdma out of your mind and just enjoy the lsd trip until it AT LEAST reaches its heights. Im talking 3-3.5-4 hours after your lsd dose time. At this point you should be at maximum saturation of lsd visuals and euphoria. During this "comeup" time I strongly recommend just relaxing, focusing on keeping yourself relaxed and breathing deeply, just going with the flow of the experience no matter where it takes you mentally. I have noticed that as I focus on my breath - slowing and deepening it, I become so utterly relaxed and euphoric that its just unbelievable. As this happens, the visuals become very fluffy, colorful, and 3-dimensional more with each relaxing breath that my mind is focused on. If things start to become tense or uncomfortable (not bad trip territory or anything just tense) - take your focus back to your breath and feel it all melt away as you exhale the depth of your lungs.
... anyway, after you feel you have reached the top and "mastered" the relaxing, visual euphoria that everyone has the choice of getting out of an lsd trip... THEN swallow your mdma tab. This immediately sends you to euphoric and visual heights that just minutes ago you wouldve never imagined possible. This method of lsd first, wait as long as possible, then drop the mdma is by far the most comfortable, euphoric, visual, and intense method for me and everyone I know. Its the best way to get the most out of each chem (much more than either is capable on their own) and has the longest duration... although other methods (at the same time, mdma right when lsd kicks in, or mdma first, lsd after - which is mainly just tripping although with a positive touch) do have something interesting to offer in their own right. Really though, none of them are even comparable... especially if you have any kind of mdma tolerance. (the mdma wears off real quick leaving you tripping only and many times disappointed you arent expecting it)