Let me tell you a little about my aunt, Amanda Cisneros, she was a good landscape artist here in New Mexico. She won countless awards of "Honorable Mention" with her work in her area of New Mexico, Truth or Consequences (T. or C.) still an award wining painter.
Now I am telling you about her because she gave me advise once about painting, and drawing. So let me share what she said, "If you need a ruler, use it. If you need a template, use it. If you need a picture take a good one and use it. Yes there are plenty of people who can draw a straight line free hand or paint a picture from memory but if you can't its okay. Never let anyone tell you that you are not an artist because you can't paint from memory or you need a ruler." Of course she also said "Don't tell anyone", but I see a lot of people using these items and not having an problems doing it.
Oh, and one more thing, never let anyone compare your work with anyone else work. My younger brother used to do that to me, his friend is good at drawing so my brother would brag about his work and try and challenge me to do the same, and tell me my work wasn't the same. Well Duh, I'm not him and he's not me. Until one day my sister-in-law told me that I could do more drawings then my brother's friend, by the way my brother's friend became my brother's brother-in-law. So I learned he is great at cartoon characters and animals but he can't draw people, which I can do all three.
Another issue some else had with my work, was when I wanted to paint a person I would sketch out the person on the canvas then I would go back and darken the best line with a pen or paint and erase the others to me that helped me with the final decision on where the arm would go or what not. But this friend of mine hated when I would do that, she told me it make my work look cheap and she thought I should learn how to create shadows and folds in the clothes instead of my lines. So I use to get mad at myself when I would catch myself doing it but now I've learned that that would be part of my style and not to be ashamed of what one person doesn't like. Beside they aren't buying my work.