But some simple pointers I can certainly do.
So here we go, 10 simple and effective tips, general and spesific.
1. Draw a LOT: Sure, techniques help, tutorials are awesome and books is teh shit, but in the end there are no shortcuts, if you do not draw a lot you have nobody but yourself to blame if you feel you are progressing slowly.
Bring your scetchbook ( get one! ) with you wherever you go, draw anything and everything, and doodle if you are on the phone, just basicly draw a lot and build up that mental library, it will only do you good.
2. Shade with the form: For instance an upper/lower arm is cylindrical, if you shade right across it tends to make it look flat even after blending ontop, if you curve your shading along it creates a greater illusion of form and 3d.
3. Vary your lines Use line variation to create form, look at early disney drawings like Mickey Mouse and Donald Duck, it may look very simple but study the lines and you can see the skill that goes into it.
4. Build up your values: I know it is tempting to just go insta-dark where there is very dark on the subject you are drawing, but if you just spend that little extra time on building the value up from light to dark you will have the option to correct things as you go along way better than if you just go as dark as you can at once, and ontop of that it looks just way better.
5. Do not be afraid to go darker: This does not mean going instantly dark, but it means that if you are afraid to go dark you will limit yourself in the range of value used in your drawing, and range of value is what ultimately creates contrast, and the eye is drawn to contrast, so if you are wondering why nobody is noticing your artwork, this might be a reason for it.
6. Squint: When you are trying to match a value, and you arent sure if you have got it right, keep the reference close to your drawing or hold your drawing up against your subject, squint your eyes and you will be surprised how easy it is to see if the values match eachother. The same applies to seeing shapes if you get stuck on the details a lot, squint and you will see the bigger shapes.
7. Check and recheck the angles: Angles and measuring is crucial to getting likeness, one off angle can have a domino effect through the whole drawing, make it early enough and the whole drawing will look off.
A good tip is to hold your pencil at a straight arm ( for lifedrawing ) find the angle and move your pencil over your drawing holding the pencil the same way to check if it is right, you do the same ontop of your reference.
8. Work from light to dark: A slight repeat of #4 but just so important, think of it as laying down the tracks before the train comes ( the train being your darker pencils in this case ), if you work light to dark you have the option early to go in and correct and fix before you solidify your work by going darker.
9. Look a lot and step away a lot: Make a habit of looking at what you are drawing a LOT, every few seconds I look at my reference to check if what i am doing is right and it really does help.
The same can be said for stepping away from your drawing and looking at it from a distance, if you have noticed how easy it is when you look at other peoples work to see mistakes, you will notice it in your own work if you step away a lot, if you do this enough you will limit your number of mistakes to a minimum. ( Also you can hold your drawing up against a mirror to check proportions, also very helpful )
10. Paper on paper: - Take 2 copy papers ( cheap paper ) cut one of them in 2 equal parts, use the big one resting on your drawing and the small under your hand, that way the paper moves on paper and not directly on your drawing so it might smudge.