Quick tip: I'm assuming you are using an instance of "Graphics" class to draw all of the pictures in the upper right hand corner. The "Up", "Left", "Right", and "Down". If you are, I'd recommend changing the interpolation mode to Nearest Neighbor so it looks more pixelated rather than anti-aliased and blurred.
Graphics g = Graphics.FromImage(image);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
// drawing stuff here
g.Dispose();
pictureBox.Image = image;
And just an idea, instead of forcing the player to only have 3 accessories, maybe you could implement a list box that contains "layers" so to speak. Players can add accessories as layers, move them up or down to change the z index and whatnot.