★★★★★
In answer to you questions:
Should I take it with meals or on empty stomach?
I always take magnesium on an empty stomach. The best forms to take are Mag Chloride, Mag Citrate and Mag Gluconate -- these are the most soluble and absorbable forms. Avoid magnesium carbonate and magnesium hydroxide -- they are badly absorbed by the body. My own favourite now is Magnesium Chloride. See this link: http://curezone.com/art/read.asp?ID=49&db=5&C0=7
Should I dilute it?
I make my own Magnesium Oil(70%-80% magnesium chloride crystals and 20%-30% water) and just take 10 drops once or twice a day in a glass of water or orange juice and drink it. Or you can also just rub the magnesium oil onto your forearm to be absorbed transdermally. You can also take it in larger doses quite safely transdermally with no intestinal or diarrhea issues. You can buy magnesium oil in most health shops.
Should I take it with calcium or get just magnesium. I am taking the angstrom sized magnesium for 100% absorbtion without diarrhea. Is that good?
Western diets these days contains excess calcium anyway -- everything is now fortified with calcium nowadays so I would just avoid taking calcium supplements altogether. This what I did, and, together with taking magnesium -- this is what got rid of my own arrythmia problems in the past. Excess calcium also thickens the blood, makes your heart work harder and also acidifies your blood and cells if you are low magnesium or potassium.
Am I supposed to hold it beneath my tongue or swallow it?
Best to take it just as an oral supplement or transdermally as suggested. Magnesium sulphate(Epsom Salts) can also be used transdermally for magnesium intake.