The infusion process can be difficult and very frustrating and trying to find answers online is like looking for a need in a haystack, there are so many different formulas that it becomes more of a science project.
Be warned that the set up below may not look pretty and could be very expensive but it does work and will keep all of your future infusions stable. You can modify this as much as you want but I can not guarantee that your setup will be stable if you decided to change anything.
There are addon mods for thaumcraft that will give you very high levels of infusion and they may or may not work with the setup below, this setup is only for Thaumcraft infusion recipes not addons but this still may work.
The basic concept of this is “there is never enough candles”, this may seem extreme but even with infusions with Very high instability the infusion was still stable.
There are 4 jars in the middle of the altar, these can be filled with whatever essentia your infusion needs:
This is very overkill and if there are simpler cheaper set ups then they can be posted.