I'm sure you've got all the help you need by now, but I still feel like saying how I personally make my fursonas for anyone else that needs it.
First, I always start with what kind of animal I want to make it. You don't have to stick with just felines or canines because those are the most popular. Go with whatever you want! For me, I either make mine felines, dragons or some form of hybrid. After doing that, I pick a gender.
Before I start designing their look, I think of a personality. This is good to start before actually colouring, because the colours can be based off of what type of character traits they have. An example of this is if they are evil. Darker colours seem to be more suitable. If they are gentle or shy, having pastel or light colours may fit. This can go for either a realistic character or unrealistic.
You can also base your fursona off yourself and how you are in real life. But, this is personal preference, so don't feel compelled to do that if ya don't want to.
Once you have that, go crazy! Add markings, a mane, whatever! Try to make it your own unique design by adding different specific details. Find colours that work nicely together and are pleasing to look at. Feel free to add items too. And if you plan on making art of your character, it may be best that you have a look that you are able to draw and it's not too complicated for you. Again, this is personal preference. c:
Oh, and don't forget a name! I usually do this after designing them, that way I can find a name that fits.
Now that you're done all of this, BAM! You got yourself a fursona. Do whatever you wish with them.
I hope these all helped ya. c: