Just a general tip: Do one thing at a time. I know some people like to multitask and do many things at once, which is great, but I honestly think you should concentrate in one fakémon at a time. No matter how hard it seems and how long it is taking. Finish one sprite before starting a new one. This way you can focus completely in the sprite you're working on. With more focus, you can pay more attention to details, and it will look better overall.
Don't stop them in the middle and start a new one. Don't leave anything to later. Do everything the way it should be done.
Here are the steps I take to make each fakémon of mine:
-Imagine a concept
-Research the anatomy of the animal I'll sprite, or the shape of the object, just so I have a more real notion of the proportion and whatnots.
-Draw in paper. It never ends up the same way as the paper, but it's a good thing to do to have a basis.
-In MS Paint, I make a square of 82x82 pixels, so that the inside is 80x80 pixels, the size limit of DPPtBW sprites.
-With this square, you can have notion if the sprite is too big or too small, and change it accordingly. If neeccessary, look up the sprite of a Pokémon that has a similar size to yours and compare. For example, if you're making a fire starter, you don't want it to be the same size as Rhyperior, who is too big for a starter, but won't want something like Happiny, which, as a baby pokémon, is too small for a starter. You'll want to compare the starter to the size of charmander, for example.
-After that, with my tablet (it can be the mouse or touchpad too), I sketch the outline inside the square. At this moment, I don't care about imperfections and details, I only check the size and proportions (Its head can't be too big for its body, unless its design needs it). I do that in red or gray.
-With black, now with the mouse, I make the outline. I use the previous sketch as a base and work my way from there. Always take care to make the pixels look clean and the lines thin. You don't want jagged corners or subtle changes in direction, they don't look good at all.
-When the outline is done, I erase all the red and prepare to color and shade
-Before making the colors, I like to do the shading. I use paint's custom gray shades to do it, being white the highlight, light gray being the base color and dark gray the shade. I do that because those colors actually have great contrast, and let you have a good feeling of the sprite before it's colored.
-When the shading is done, I make the palette. I think this is the most important, but the most difficult part on spriting. You need to take care to choose colors that fit your pokémon's personality and attributes (green-colored pure fire type? no, thanks). The saturation and contrast between colors is hugely important. You need to be able to see the shades and be able to tell where one color ends and another starts, but they can't jump off the sprite with contrast (you'll hardly use pure white or pure black, for example).
-After that, I do the final polishing. I look for fails and things that could be improved and change it the way I think it will look better. More than once, I had to change the whole outline because I disliked the pose; or the colors, because they didn't fit what I wanted the sprite to look like.
Zoom ou a lot all the time, to see if you like the outcome so far. Also, always work on copies. When you finish something, copy and paste it and start working on the next step. This way, if you dislike a change and run out of ctrl+Z, you still have a safe copy to start again.
These are just some general tips that should help you on making even greater fakemon =)
Well Thank-you very much for taking the time to write such a lot of tips.
I have had a look at you thread, you know what you're talking about
:).
Sadly i cannot do some of the things that you do;
I am a terrible artist, cannot draw for my life.
When i make a sprite, i draw random shapes until something looks like a feature that could be used, however; when i get a good idea for what i want to draw i will use the square border idea, lots of spriters use that idea.
I also make lots of sprites, they are kinda my ideas, after I have lots of fakemon i will colour and improve.
Well here is a sprite i just made,
Maybe a steel/water type.

This or This?
its evolution will maybe be a sword fish or something..?
(EDIT)
Possible colour;
I kinda copied Steelix's cheek, i didn't copy and paste, i just did the same sort of shading. :D
~Kian