Taste as you go. You can always add more flavoring agent if you want a stronger infusion, but you can’t take it out if it’s too strong.
Keep in mind the potency of your flavoring agents. Some, like herbs and spices, can be quite strong and may need less time to infuse.
Label your syrups with the infusion ingredients and date to keep track of flavors and freshness.
Experiment with different combinations to find your favorite flavors for cocktails.