What kind of cinnamon? The kind you find in spice packages at the grocery store? That's cassia. It's related to cinnamon but medicinally speaking it's not true cinnamon. Cassia is much higher in coumarin than ceylon cinnamon, so it has more of a blood thinning effect, and it's anti-inflammatory. Ceylon cinnamon controls blood sugar and in particular lowers insulin resistance, is anti-microbial, and has a better track record with digestive disorders. You usually have to take the oil of it to see strong benefit, but I've made tea with it daily during bowel flare ups and it helps. Some people claim it fights candida overgrowth but I think that's mostly BS... if you want to fight candida albicans you need to make your own probiotic ferments like kefir and sauerkraut. You can't kill off something that's native to the body, all you can do is balance it with other types of healthy microbes.
Garlic... I've mainly used it when I feel an infection coming on. Crush up some and leave it exposed to the air for 10 minutes to enhance the allicin content, then swallow the pieces with water without chewing. Avoids the bad breath.

Dried garlic tablets are useless, best to use the fresh.
Turmeric... I've used for inflammatory bowel disease and it helps a lot. It works best when combined with black pepper because pipperine delays your body from breaking down its curcumin content. I used to make my own turmeric pills with gel gaps that were 90% turmeric 10% black pepper. It really helped. The only problem is that it thins blood and when I cut open my finger I was bleeding forever, so if you have any bleeding disorders I wouldn't do it. Also... those turmeric extracts on the market? Not nearly as good as just taking raw turmeric in pill form.
Heating up turmeric in some kind of fat releases more of its medicine. A popular beverage is 1 heaping tablespoon of powdered turmeric to 1 cup coconut milk. I don't find it very efficient though, and who wants to drink something that fattening once a day? It does help though.