A drawing is complete when you have nothing more to add to it. It is finished when you feel you have done enough. It is as simple as that.
But one or two points occur to me that might help you arrive at that decision. Fill your page completely, from top to bottom and side to side. The reason for this is, that before you can confidently leave out, you must overdo what you put in. The same applies when you are concerned with studies of single objects, or details, that you are going to incorporate into a larger work. It is also easier to frame a completed drawing in your sketch book. But never tear out a picture if you can help it. Keep a sketch book intact.
If you want a particular scene framed do another version of it from the original sketch. Sometimes, however, it cannot be avoided. A sketch book picture has to come out. But do be careful when doing so. It is easy to tear your drawing and your sketch book as well. The binding will become loose and all the pages fall out.
I have suggested that using a viewfinder is helpful in settling the problem of what to draw. However you may want to do the view next to the one you have chosen. Add that view to the one you have already completed, either on the page opposite or by adding a further section. This can be attached with tape quite easily and will fold into your sketch book neatly. You can, if you want, continue adding as many
sections of views as you like, folding them into your sketch book and attaching them with masking tape Any change of tone, or even style, from section to section will not harm the total effect when you pull out the finished work. On the contrary, it adds something to it.
Remember, though, the view must continue from one section to another. The lines in a panoramic drawing must move easily from drawing to drawing, else it will look odd.
TIME MARCHES ON
It is not always possible to devote hours to one work outdoors. This fact must be recognized. Rain, disturbances, limited time available, will tend to cut down the time you can devote to a picture or drawing. This need not deter you, however, from producing any finished work. If you are very short of time, go for quick lively sketches. Make lots of notes that mie:ht help you and finish them up at home. Also, with a more ambitious work, if you cannot complete it out-of-doors, finish it off at home.
It is best to do lots of rough studies of a scene, plus one or two careful details and a few written observations. Then, when you get home, assemble the material into a completely new picture.
Making up two or three half-finished sketches into a completely new work is one of the things I shall be discussing in the chapter on composition. For the moment, let me say
this. Outdoor drawing and painting is the best source of
ideas. It should be persevered with and will reward you in many ways. As you will have realized, there are few rules to bother about. The approach I have taken is purely practical.
If you have drawn inside, you will be able to draw outside.
There is no hard way and there is no easy way. There is only your way. And that is the only thing I want to encourage you to develop. If you are in doubt, or find your spirits flagging, go and look at the drawings and paintings of those great artists who have got their inspiration from working outdoors. Turner, Constable, Samuel Palmer, Cox, de Wint and, in our day, Carel Weight, Ruskin Spear, John Minton, Edward Bawden, etc. There are many of them and their works will help you. By relating your problems to these works you will find not only help, but appreciation as well.