Introduction to iPad Sketching
Here are some tips and tricks that have helped me. Of course creating art is a personal experience, and what works for me may not work you. The products and apps discussed here are based on my personal experiences and are not part of a paid endorsement.
The Stylus
What really made the difference for me was the stylus. I use the Pogo Sketch stylus by ten one design. It's basically a quarter inch in diameter aluminum tube with a tip made of capacitance foam which allows it to react with the touch screen. I should note that there is a significant performance difference with the Zagg Invisishield protecting the screen and the Pogo stylus. The stylus works better without the Zagg Invisishield, I haven't felt that the degredation of performance warranted removing my screen protector. What make the stylus a necessity for me is knowing where the "tip" of the brush or pencil is on the canvas. Just using the tip of my finger gives too much ambiguity as where I'm drawing.
The App
There are several iPad and iPod drawing apps to choose from. There are a number of features that I look for in a drawing app. The first is multiple layers. If you're familiar with applications like Photoshop then you'll know what I mean. If you're unfamiliar with layers, think of it as drawing on acitate or glass. You can see through to the layer below and you can erase or reposition the layer above without affecting the layer below. This offers a high level of flexibility.
My chief complaint about these apps is the resolution. With the exception of the vector-based drawing apps, the resolution for most is 1024x768 or 1024x1024. Print-quality which is 300 pixels per inch gives a nearly a 3.4 x 3.4 printed image. This is not ideal if you're looking to publish your works or print them for a gallery. This is still a great way of getting ideas down quick and to publish on the web.
My personal favorite app is Sketch Book Pro for the iPad by Autodesk. I have ArtStudio and Paintbook. Judging by the various videos on YouTube, the application called Brushes also seems to be another popular app. Sketchbook Pro offers a wide range brush types from charcoal and watercolor to some more unique brush patterns. I find Sketchbook Pro to be to intuitive to use. It also gives me the option to save out a Photoshop file.
Other Tools
It goes without saying that you should have an iPad case to protect your investment. I chose the Dodocase. Because the Dodocase replicates the look and feel of a sketchbook, it just feels natural to me. Also it's more discrete. The Dodocase is not meant for rugged use and if you hold the case open at more then 90 degrees, you do run the risk of having your iPad slip out.
A number of artists use a fingerless glove to prevent the palm of their hands from making unwanted strokes on the screen. I find that it's just as easy to rest my hand on the edge of the screen. Perhaps as the temperatures get cooler I may try the fingerless glove.
I hope this information was helpful. As with any artistic medium, practice makes perfect. I plan to follow up with product reviews and other information. So check back.