As a amateur artist who is himself still learning how to make a proper picture, I feel rather unqualified to be dispensing advice to others. However, since our benevolent administrators have given us this new board, I thought I might make use of it and post a random collection of tips, suggestions, and hints that I have picked up along the way. If you have any real artistic experience, you surely know all of this already - this is mainly for the folks who have posted a picture or two in the communal gallery and are casting about, wondering how to get more than a few comments.
Some of this is general advice. Some of it is about making SPANKING art. General art advice is everywhere. Go looking for it if you really want to be a good artist. If you can draw vanilla pictures, you can draw spanking pictures. Spanking art advice, on the other hand, is harder to find. To some degree, I question its usefulness, but... what the hell.
Read the other tutorials thus far posted. CM_Zero and Rak offer sage advice.
Have a good idea. If you've fallen in love with an idea and feel like you just HAVE to put it to paper or the world will end, you've won half the battle already. Think about your favorite scenarios. Think about your deepest, darkest desires that you wouldn't tell anyone about in real life. Draw them. I always make the best pictures when I am 100% emotionally commited to what I am drawing. If you want to make quick pictures about things you only half care about, no one is going to stop you. However, I guarantee you will do better if you only draw when you are excited to do so. For example, right now I have at least ten ideas for pictures floating around in my head. Only, say, half will ever get made - I won't end up caring enough to do the other half. Of the half that will get made, currently only two ideas have me hooked enough that I am actively planning to draw them.
Thumbnail like a madman. I think this counts double if you will be making your pictures on the computer, since it is harder to sketch on a computer. The first time your pencil touches paper, that pencil SHOULD NOT be anywhere near your final piece. Do some one-to-five minute sketches with no regard for the dimensions of your final picture. Then think about the proportions of your final piece. Draw a bunch of thumbnails with those proportions. Change the size of your canvas if you need to. Your idea might change significantly while you are making thumbnails. That's good. You are trying to make your idea as good as possible before you start your final drawing. Which brings me to...
Use an interesting perspective. In vanilla art, we take it for granted that pictures should be pleasing to look it. In spanking art, many artists (myself included) are tempted to simply draw a spanking in progress, without much thought given to showing it at an interesting angle. Your picture will be much better if you avoid the common trap of simply drawing a spanking scene happening in the middle of the page, straight on at eye level. When you're thumbnailing, try some different views and angles!
Faces are the most important thing. Even if you disregard every other piece of advice offered to you by anyone, please spend some time on your faces. The emotions involved are the most important part of a spanking scene, and emotion is largely conveyed through faces. If you have to draw someone's face five times before you are happy with it, do it. Twenty times? Do it. Don't stop until you are satisfied. Even if spending all of this time drawing faces makes other parts of your picture suffer, do it anyway. I cannot overstate this point.
Asses are also important. Obvious, right? Don't splotch some red paint on a character's ass and call it good. It's not good. Some artists do it all the time, but you can do better, without much effort. Look at a picture of a recently spanked ass. See all those different shades of pink and red and even some bruising? That's what you want.
Read some books. You are drawing spanking pictures. Spanking pictures are porn, not fine art. Lots of books are geared more towards real artists looking to make masterpieces. Which books have I found actually helped me draw better spanking pictures with a minimal investment of time?
The Artist's Complete Guide To Facial Expression and
Perspective Without Pain. I picked both of these up recently and they've made me a better artist already. The first is an excellent guide to facial expressions, and covers both realistic and cartoon drawing. The second is a very gentle introduction to perspective and depth. The great thing about both of these books is that they are fun to read. Just sitting around and leafing through them will improve your art. The facial expressions book is also an excellent reference - if you ever need to draw THIS KIND of face, or THAT KIND of face, it is full of tips for doing so.
Closeups are your friend. Plan your picture. Now, move the viewer's eye in a little bit closer to the action. Look better? It probably does. Keep moving in until your picture stops looking better. Spanking is an intense, personal experience. Long, wide shots do have their place occasionally, but I find that closeups usually work much better. We all do it from time to time, but you want to try to avoid the whole people-in-the-middle-of-a-big-empty-room-spanking-each-other feeling.
Copy other artists. No, not for your final pictures. But copying other artists WILL help jumpstart you into developing your own style. Me, I tried to learn from Cc and Kamitora (God bless them) and took it from there. Pick a few of your favorite artists and copy some of your favorite parts of their best pictures. This is especially true with faces - find some faces that you like and trace them. It's pretty quick and easy and helps a lot.
Use photos. It's not cheating. Google Images is your friend. Or if you're lazy, or you can't find the right pose or position online, take pictures of yourself. I've done it. You don't need to adhere strictly to what you see in the photos. Sometimes just the reality-check of looking at a photo and saying "ohh, okay... her shoulder should be down there" is all you need. Consider referencing photos for inanimate objects as well - implements, pieces of clothing, etc. Spanking is a sexual kink. Sexual kinks often involve fetishes for objects. Maybe you love rulers as implements, or lacey underwear on a lady, or whatever. Make it look right by looking at a photo. You'll be much happier with the finished product if you do.
Don't post huge pictures. I'm sure this has been said before but I will repeat it. About 1200x1200px is the largest I'd go, personally. And that is only if you really, truly need all of that screen real estate. For a simple picture - just a regular spanking - cut out as much whitespace as you can, and size it down so the main characters actually fit in a normally sized browser window.
After you post, check obsessively for new comments. Everyone does it. Join the party!
Well, that turned out a bit longer than I expected.
Bottom-line: have fun. I consider making good pictures to be fun, thus I offer this advice. If your idea of fun isn't working hard at making the best pictures you can, that's totally understandable. Some of you all out there have lives, after all.