OK, I think a lot of people are confusing
writing with
drawing.
Sounds like you want to do more freehand type sketching vs. controlled technical drawings, right?
I'd forget about drawing on moleskin. If you're serious about drawing, draw bigger. Smallest paper you should draw on is letter sized. The most used type of paper I used was Letter and Tabloid sized paper, because you can buy reams and reams of it really cheap at any office supply store.
It's been awhile since I've drawn with old school analog pens, but I'll chime in with some of my old favorite before I went all digital.
In a nut shell, you'll probably need three types of pens for drawing.
1. Ball Point Pen - This one is a must for sketching. You can draw really fast, and it has almost a pencil like quality to the lines than other pen types. I really can't recommend a single brand as everyone draws differently. I recommend trying a whole bunch. For lighter sketching, try good old fashioned Bic Ballpoints. Their inks tend to not gum up too much with build up, but don't lay down as much ink as others. Otherwise, buy a whole bunch and try them out, you'll eventually find your favorite. Best part is ball points are cheap. The cheaper the better, because they are usually light weight, which is better for sketching. Mont Blancs and Parkers make poor drawing tools.
2. "Flair" Marker Pen - Papermate Sanford Flair felt pen is the brand I used all the time. Often used in conjunction with ball point sketches to draw over the light ball point lines. Felt tip pens are great for making bolder lines, outlines, and shadows. Another great thing is you can still sketch very quickly. The down side, is you'll go through them really fast. They lay down a lot of ink quickly, so they dry up quickly.
3. Rollerball Ink Pen - Pilot brand is one I often used. They come in a variety of tip sizes. Try different brands and sizes. Avoid "Gel" type pens, as they gum up quickly, line quality usually sucks as they skip a lot, and take forever to try. Rollerball Ink pens are great for more controlled type sketches.
Now for more expensive pens for more controlled drawings buy Pigma Micron pens. These are the best alternative to Rapidiograph type pens. While it's cool to have expensive Kohinoor metal pens, they are really high maintainence. Letting one dry out will be an expensive mistake, as the tips are difficult to clean out, and will probably never lay down a perfect line afterwards. And either way, the really fine points were a real PITA to draw with, as the fine metal nibs often snagged the paper surface. But old school Rapidiograph drafting pens are obsolete since all control art is done on computer now. Buy cheaper disposables that you can still draw with. Buy some Pigma Microns. They're the best, and they last a long time.
If you're serious about drawing, stay far far away from fountain pens, and anything that says Mont Blanc on them. They are fine
writing instruments, but they are not ideal for
drawing.
But again if you are really serious about drawing, don't use pens. Use pencils. And I'm not talking #2 Graphite pencils. Try Prismacolor and Verithin colored pencils.
And if you want to make a career out of drawing, go digital. Learn Photoshop and pick up a graphics tablet like Wacom.
-Ed