It may sound simple and obvious, but your choice of drawing media has an enormous influence on your ability to do certain things. Your tools can either help or hinder your process and your overall development as an artist.
Our drawing tools are chosen through aptitude, personality, necessity and accident. Its a good bet your drawings and paintings will have a similar character, as you'll be more inclined towards line or value, precision or effect. Look at Rembrandt and Ingres:
Its very obvious the sensibility remains intact from drawing through painting. The artist's nature (skills and temperament) and nurture (schooling and societal standards) come together and are harmonious with the end result. While their approaches are quite different from each other, the goal still falls within the range of describing an observed subject.
As fantasy illustrators we have more tools, choices and unique problems than ever in the history of art. The simple (and powerful!) pencil can be replaced by a myriad of media choices as well as the computer. As with many things in art, you'll be better off choosing your materials wisely and informatively, allowing you to have the proper means of expression to move forward and create with.
I make no claims to being a great draftsman; in fact I feel I'm just starting to delve into drawing after many years working on the computer in the games industry. The majority of my drawing in preparation for digital painting was done in blue pencil, which helped in visualizing and constructing 3-D form, but hindered me in grasping the "whole" or tonal plan of an image due to the blue pencil's inherent lightness, and the computer's inherent forgivingness. Additionally, because this type of pencil can't go very dark in value, I was "let off the hook" for making finished drawings, and ultimately tackling nuanced characterizations and precise details. Blue pencil is a common choice for drawings that need to be "built up", "drawn through", and erased frequently. Comic artists use this medium as the pencil can be inked over and the blue linework fades away and does not photocopy. My personality is both a bit safe and thorough, and this blue pencil drawing allows me to remain in my comfort zone and do complicated things.
The opposite type of drawing which aims more for gesture, feel, and naturalism can be found in my friend Paul Rhoads' work:
Utilizing a soft pencil, Paul deftly indicates light and shade, capturing a feel of the final painting in the drawing itself. Note the broken contour linework of the nude's back, which suggests light interacting with the planes and form. His sensibility in these quick sketches can translate into drawings that stand alone as works of art, while my blue pencil constructions are clearly more suitable to a process and not a product.
While Paul's beautiful drawing style contains much to admire, I still find it necessary to come back to methods which allow for construction and complexity of forms and viewpoints.
Below are a blue pencil drawing and some converted to black and cleaned up on the computer, for comparison:
I'm pretty useless at drawing straight on the computer... even though I use a cintiq, I cant seem to use it for more than cleaning up and manipulating pencil work. Having said this, my friend Joe Wilson is superb at clean, constructed drawing done solely on the cintiq:
The computer easily allows for varied line weight and unlimited malleability and erase-ability. While not as varied or nuanced as Paul's pencils, Joe displays clean and descriptive forms that provide the framework for a digital painting.
Switching back to that "fine art look" again, we can see clearly with this example below the huge gulf that can exist between the beauty and naturalism of the soft-lead pencil versus the consistent, mechanical mark-making of the blue pencil and computer. When the model is in front of you, there is great truth and economy in using a tool which can be immediately employed for any effect.
As illustrators, we dont generally have our models (dragons, goblins) in front of us, nor are we generally producing drawings as a final product, so have to be comfortable with tools that allow for a building up and exploration. Notwithstanding, the end result is still "art", and our tools have to be optimal for the various processes and stages of art-making.
While each tool has its own advantages and drawbacks, there are some instances where there is a preference. Paul's quick composition sketch is proof that a darker, more immediate drawing tool is preferred for the early stages of ideation. A wash is also invaluable for establishing that essential value planning from the outset as shown here by one of my favorites, Tiepolo...
I also noticed at illuxcon that some of the tighter illustrators used a cheap mechanical pencil as their tool of choice. I also noted one who used that type of always-sharp pencil also had a soft pencil for his thumbnails for the exact reason of choosing appropriate tools for the creative stage.
The point here is just to call out the importance of choosing your tools as appropriate for the stage or intention of the drawing. While you may be comfortable with one medium, it may be what's holding you back from certain results, both aesthetically and developmentally. Eventually I would hope to develop methods that blend the best results of the illustrative/constructive approach and traditional/natural method. For now, I keep in mind and consiously change my tool for that stage or problem that is being addressed.
Finally, here is another Tiepolo that beautifully contains both precision and naturalism and hints at things to strive for...