Oh, I’ve been dreading this topic, just dreading it, but I feel like I need to address it.
I hate doing still lifes.
They drive me bonkers. I’d much rather work on the figure all day than do anything involving fruit, or bottles of wine, or white objects.
However, I feel as though I should mention them as they are still important for art education (I just hate them).
Still lifes are great for learning the basics. In particular, they’re fantastic for having a cheap model. While I am hugely in favor of drawing from photos, every artist must learn to draw from life. There are things that you learn from drawing from life that just aren’t apparent in a photo. In particular, it’s very difficult to understand three dimensional form when looking at a flat picture. I feel like all artists need to learn that from life, particularly in the beginning.
Still lifes are useful for studies (where you draw with a particular focus) and for practicing composition. They’re also fantastic as they are cheap models and will hold very still for a long time.
There are two main types of still lifes that I usually see.
The first is the form-training still life: these consist of the basic shapes: cubes, spheres, cones, etc. usually painted white though sometimes clear. The poor man’s version of this is getting some square boxes (the square kleenex boxes may be a good choice), kid’s party hats, and balls (the kind that you get at the grocery store for $5 are fine). For cubes, be aware of whether there cubes are actually cubes (all six sides are square).
The second is the “more artistic” still life: these consist of things like flowers, fruit, other foods, etc. These are fantastic for learning more complicated shapes, and practicing color, lighting, and mood. They can also be great for texture and other rendering.
So, while I’ll be talking about perspective later, I’m going to give you a brief “How to” on drawing fruit or other organic forms. When drawing an organic form like fruit, the easiest way to do it is lightly block in everything first. What I mean is just a general shape (e.g. a apple becomes a circle). This will allow you to get the overall proportions for the whole composition.
Once you have your basic shapes blocked, the easiest thing to do next is find the axis of the fruit. This easy in fruit because they have little indentations at the top and bottom, so use that! If you’re having trouble seeing the tilt of the axis, stick toothpicks in them! Your axis will likely not be straight up and down, straight left to right, or straight in and out; however, you can break it down thinking in terms of how left to right, how up and down, etc. You can use three dimensional arrows to help show yourself where it’s going. You can also try lining your pencil up with the axis to help yourself see where it’s going in terms of 3D space.
Once you have the axis drawn, you’ll probably want to do “equators.” What I mean is you’ll draw around the shape as if you were cutting it in half. This means that you’ll have a total of three equators and they should all be perpendicular so it looks something like this:

(Source)
It looks complicated, but if you do them one at a time it won’t be so bad.
If you’re doing a shape like a pear, you may want more horizontal equators than just the one. For a pear, I’d recommend about 3 - one in the thin section, one in the fat section, and one showing the border between the thin and fat sections. However, it’s really what you need to understand the form. I can’t give you the magic answer.
Hopefully that mini how-to made sense, let me know if you need a demo. Also, I know there may be others like me out there who are less interested in still lifes, but I keep reminding myself that while I don’t have to like them, I’ll always need to draw people holding and interacting with objects; in addition, environments will always have elements of the still lifes. It’s excellent training.