What motivates you as a writer? Do you do it because you love to write? Are you doing it for a living? Do you enjoy getting an occasional check in the mail? Do you love to see your byline? What makes you sit down at the computer, or pick up a pen and notebook?
For me, it's a combination of things. I've always felt more comfortable with the written word than the spoken word. I find it difficult to speak in public. In classes, I prefer reading the material to hearing a lecture. It seemed natural to me to gravitate toward writing as an outlet.
Don't get me wrong, I do enjoy getting a check. In fact, I rarely submit my work to non-paying markets. I will submit when I feel the market is well done and professional, such as Stories for Children Magazine. I like their philosophy of trying to make stories available for free to children everywhere who can read English, so I submit to them.
When I first started writing, I was more excited about seeing my name under the title of a story or article. Back then, I would submit to anyone whether they paid me or not. I loved being able to tell people I had a story or non-fiction piece published. I still get excited when something is accepted, but there's a lot more to get excited about when there's a paycheck.
Still, the motivation of getting paid or seeing my name in print isn't always enough to get me working. For me, the motivation comes more often in the form of an idea. An article I might have read will get me to thinking of what else could have happened. A newspaper story might lead me to an interview with an expert whose story needs to be told. Unfortunately, these ideas don't come to me every day, but I try not to feel guilty.
Awhile back I sent off an article with quotes from successful authors about how they organize their time and what they hoped to accomplish. The editor of the magazine rejected it because it made her feel guilty that she didn't do as much as these other writers. She was afraid her readers would feel the same way. For me, what others accomplish sometimes acts as a motivator. If they can do this (oftentimes while raising young children or working full-time away from home), then surely I can find an hour or two a day. Still, as I said above, I don't feel guilty when life gets in the way.
Find your own motivators, but don't wallow in guilt. Find what sparks your interest and write when you can. Enjoy your craft, don't let it become depressing because you feel you don't write as much as you should.