The Base
For most syrups, I use one and a half cups of Demerara sugar to one cup of water, plus whatever spice, fruit or vegetable I'm using for flavor.
Heat the water in a pot, then add the sugar and stir for about four minutes, until it's fully dissolved. Don't let it boil — it gets too hot. If it starts to, just take the pot off the flame for a moment, then put it back on.
Then add whatever I'm flavoring it with, and stir anywhere from 2 to 10 minutes depending on how tough the ingredient is. Something like bell pepper needs about 10 minutes; chili is closer to four.
Once it's done, let it cool for a day or two, then bottle it.
I always use Demerara sugar — you can find it at 7-Eleven and Tops.
Tamarind
For tamarind syrup, I use a chunk of tamarind paste from the local market. Cut it into small pieces and soak it in warm water for about an hour, then pick off the fibrous strings. Regular tamarind is a little too tough on its own, so softening it first makes all the difference.
Mangosteen
For mangosteen, I cut the fruit in half and throw away the big pieces that have a seed inside, keeping only the small seedless pieces. The rind gets thrown away too. Five to ten fruits is enough for a batch.
Orgeat
For orgeat, I swap the water for almond milk. I use unsweetened single-serve packs of Almond Koka from Tesco — two packs go into the pot. Heat it up (again, don't let it boil), then add around 2 cups of Demerara sugar and stir for five minutes.
Let it cool for 30 minutes, then stir in a quarter tablespoon of vanilla extract — I use the McCormick brand from Tops. Then let the whole thing cool for 24 hours before bottling.