It's a tough one. I get how you're feeling. That's how I ended up here lol! All be it several months late lol!
I'm getting quite frustrated too.
I've been tryna get my head around making sounds on plug-in / vst / in the box synths for over 3 years now and still end up just random tweaking and guessing half the time. I started my journey using Reason 6 and now use
Reason 8.3 and have used Logic Pro 9 / X,
FL Studio 10 and Ableton 9 also.
The subtractor and Thor in Reason are very very good synths for learning synthesis I might add. Especially Subtractor for it's ease of use and how it's laid out, quite easy to understand how each element works, pretty clear and also looks cool as well which is a bonus.
Anyway, for me, I understand how synths work:- broken down it's - oscillator to filter to amp, with modulation thrown in for good measure. I understand you use 2, 3 or more oscillators, how the oscillators vary in sound, sine - triangle to saw etc and that you layer them up and change the semitone perhaps. I understand you use the filter to cut off or open up frequencies and how ADSR works but really what I feel it comes down to, is knowing what sound you want to make in the first place. That's half the battle.
I make house (mainly) and I've gone back to presets really (
Korg M1 - as they're great) but for me, there's no satisfaction in making an electronic track if the sounds aren't your own. So back to what I said, you have to really understand what kind of sound your after. If it's a bass sound, then what frequency range should the bass sit in (I guess), what timbre are you aiming for, does it need reverb, does it need distortion or anything else that that genre requires or has predominantly. So I'm going into now, getting my head 'round what sound house music is looking for in each element and trying to understand what the timbre / texture and overall feeling / purpose is for each sound the people who make sounds for house are aiming for when they make their sounds.
Some online stuff that may help:-
Look up the Petti Test on You Tube. The guy in those tutorials reverse engineers sounds using Reasons Thor and Sylenth I've seen him use as well.
I did the first free part of Syntorial as well, very good. One thing I picked up straight away, which you would've thought was obvious, but if you use the cut off to remove frequencies, then you should turn the amp volume up a bit to compensate. Also, that a square wave at high octaves, sounds very much like a saw tooth at high octaves. Say Octave 5 or higher, it doesn't at low octaves. Interesting. I would've paid for the full syntorial if I'd had the money, it was definitely working. I was definitely hearing things and understanding how the different waveforms (sawtooth, triangle, sine etc) sounded different, getting to hear them well. Think it's probably worth it's money to be fair.
Another thing that I was told to do ages ago (which I did try with Subtractor on Reason but took about an hour for each and found I didn't really learn or remember anything lol!) is to find a preset / patch you like, and then open up another of the same synth, and starting with the oscillators, adjust the parameters on the duplicated synth to make the same patch. I might try this again actually with a new approach. Try listening really attentively to how each element is altering / sculpturing the sound. Try and understand what each tweak / change is doing purposefullly.
It is a mindfield isn't it, lol!
Good luck