Dont slavishly put in everything you see, make decisions about what you want to say in the painting. Is it about bright sunlight glinting off things in the afternoon sun? Are there enough fine lines and shapes in your painting? Make things up and add them in or combine the best bits from several views. Something that I do is have an image of a painting that I've done successfully of a similar type of image
The final advice for this series on composition is about the inclusion of figures.
When you add a figure it instantly gives a feeling of life, rather than an empty still scene there becomes a narrative.
you can see in this I have painted three different people, they are only suggestions of a figure, the eye fills in the details.
A good tip that I was advised to do was to take a photo of your painting and load it into a paint program like photoshop. When its there you can practice placing a figure in different places to work out what looks right and what scale. Remember that if your painting is from an eye level view that the heads of any people need to be all at the same level no matter how far away they are, their feet will just end further up the paper if theyre further away and further down if they are closer. A good tip would to be to drop a tiny mark where their feet will be and a mark where their head will be then you will have an idea of scale for filling in the rest of them.
dogs are also fairly simple to drop in with only a couple of strokes needed:
cows are one of my favourite things to add because they are pretty much black and white splodges with a straight back and angled neck.