Creating first OC in Photoshop

[altoeclipse 3]

I want to start creating my first OC in Photoshop. Problem is knowing where to begin. I want to avoid tracing, and it's going to be a young unicorn stallion. I'm not too good with sketching despite having the description of my OC on paper already. To be honest, I've never made an original character previously, but I really want to go for it this time round. A D-I-Y, if you will.

[Snow 7,338]

The secret sauce is references! 

A written description is indeed good however having a visual library to help guide you trumps all, It is incredibly difficult to draw something you cant see, especially if just starting out.

Nice colours? they goes onto the canvas for sampling.
Art with a mane/tail style very close to what you want? on the canvas it goes.
A pose you want to emulate? on that canvas at once!

There is no shame in using the freely available pony bases, they are good to draw hair and features onto or even using one of those OC creating sites or games like Ponytown for a bit of inspiration.
This is just the first step for having a rough example of the character you want to make visible in front of you (you needn't share any bases or tracing) at this stage you can try a number of hair styles, play with the colour, so on. Make a number of small versions and compare them.

Once you are fairly happy with the rough stuff you can try drawing from scratch with your references visible at all times, pick a corner out of the way but close so they are always in view 

A great start is using 3 light circles for placing the head, ribcage and pelvis, from there you can work out where the legs end and rough out the mane/tail. always checking in on your reference(s) and taking a step back so to speak to make sure everything seems well placed.

I dare say the most difficult part about drawing a pony is the face, look at how others have drawn the muzzle, where they eyes go, that sort of thing, little good will come from trying to guess it!
There is so so much I am not saying so I highly recommend checking out some art videos and other resources  all the best!

[altoeclipse 3]

Nice! Sounds good to me!