Basic Methods:
One can easily create a straight animation by using either hand drawn technique directly on paper or completely digital by using software's like-Toonboom animate pro, adobe flash or PAP like open source software which are available for free online.

As described above while animating straight ahead; plan your animation and then draw your first drawing and continue spontaneously till the end.

While animating, do keep a check of volumes of your drawing (in case of character animation).

Also, one can go a step further and try different camera movements to create more dynamism to the action and explore the technique further.

Skill Set:
One need not be a master in drawing to animate straight ahead but yes; one should be creative and imaginative enough to explore possibilities of this technique.

But for complex character movements, fight sequences and camera moves one needs to be comfortable with basic drawing skills.