fursona 101..?

They are pretty hard, I'm not gonna deny that. But, uh, the best advice I could give right now is continue experimenting and playing around with different things. Maybe think of things you like and incorporate it to your design.

Foods, colors, objects, what species of bird you want your fursona to be if a bird is what you wanna stick with, etc, etc.. 

You could also look at references to get some inspiration, too!

well I'm a furry artist so I might give some tips

first of all is of course the species, you already want to make a bird sona so you got that out of the way.

now as you have your species think about things you like, your fav color, your fav food, music you listen to, your vibe overall and try to put it on canvas.

Lets say your fav color is yellow, make your bird sona yellow and from that try to build your sona, maybe take some inspo from irl, my sona for example has similar body type as me and similar haircut as me irl, I make him wear dark clothes and metal merch since that's what I'm usually wearing irl, I drew him as a shark with dark gray skin and purple-ish elements like his hair, eyes, inside of his mouth and ears and tongue, because I like sharks and I like dark colors and purple. 

Hard agree on the commenter above me, taking aspects of yourself is a great way to design your sona and i love when ppl do it :) personally mine also has the same haircut as me (kinda), they have my moles and my eye shape. I also like taking inspo from character designs i like, whether it be from other sonas or anime or even irl photos. Dont be afraid to take parts you like from different sources and just slap them all together!