I'd say either stick to 150mcg LSD or lower it depending on how psychedelic you want your trip to be. MDMA intensifies the LSD, and vice-versa as well so take that into account. I personally prefer a more psychedelic candyflip and would definitely lower my MDMA dosage if I were you. MDMA quite easily overpowers LSD. Take enough MDMA when by itself wouldn't feel like it's quite enough, and adjust your LSD according to how psychedelic you'd like your trip to be. If 150mcg is your sweet spot I'd probably stick with 150mcg or aim for 125mcg depending on how well you can handle intense experiences, nothing lower imo. 100mcg was quite underwhelming in my experience.
As for timing, I'd say first take the LSD, then take the MDMA anywhere between 3-4.5 hours. Timing is key, but it's also difficult and it's something you have to learn through experience or luck. I'd say take the MDMA whenever your LSD smoothes out and you feel comfortable enough to take the MDMA. Don't make the same mistake I did and take the MDMA in hopes of turning a bad trip into a good one, it doesn't work.
For a little extra information, the combo is quite intense. The come-up of the MDMA is what I found to be the most intense part of the experience, and it may cause some anxiety, but ride it out and you'll be having the best time of your life. If you're going to be doing it in a public area (like a festival) you have to be completely okay with looking fucked up. Also, besides potentiating the effects of both drugs it also lengthens the effects of both drugs. 150mcg LSD and 120mg MDMA had me going, from the beginning of LSD till the end, a good 12 hours. It varies with the dosages though as my 100mcg/90mg candyflip lasted a relatively short 6-7 hours.
Practice the same HR as you would if you were to do just MDMA. The emotional aspect of the comedown is quite similar to or even better than rolling alone, but I find that your body feels more beat up.
You'll love this combo and will probably prefer to candyflip every time you plan to roll instead.