Simple syrup: Am I over-complicating it?

I'm very new to playing around with cocktails (mostly whiskey at this point) and one of the the things I've been struggling with is my simple syrup. I see a lot of recipes call for simple syrup without giving any other details, but I also see a good amount of variation among YouTubers, websites, and the like talking about whether they use 1:1 or 2:1 syrup which makes it hard to keep track and judge which a recipe is actually expecting. Is 1:1 generally the default assumption? Is there any reason to keep both on hand rather than just adjusting proportions when I do manage to figure out which one a recipe is assuming?

The other place syrup has tripped me up is Demerara syrup. I've made a Demerara syrup (2:1) and tried it a few different times in basic cocktails (mostly Old Fashioneds to keep it simple as I play with ratios) and even in smaller quantities than I would use for a white sugar syrup (also 2:1), the molasses-y flavor has been really strong. Do people tend to use less Demerara syrup than an equivalent white sugar syrup or is there something else I might be doing wrong with it?