First step, you have to do when are starting to draw a new graphics is to determinate its' size. You have to remember, that TTD uses non-proportional graphics and you have to somehow fit in with you graphics. You have to decide, what sizes you use. For example, my long bus is longer, than a big house. In reality, the bus is 12-15 meters, a big house is at least 50 meters, but in TTD scale houses are diminished in comparison with road vehicles.

Some objects are size limited. For example, train cars. The game hard codes their sizes. TTDPatch allows you to make them shorter, but not longer. The same problem is with buildings, industries. You can draw sprites larger, than intended, but it leads to the graphical glitches. Long vehicles, for example, have glitches in tunnels, on slopes, bridges. Decide, what glitches are you ready for. If you want no glitches, you have to fit the size of the default objects.

To make sure your graphics look good, you need to make it self-proportional. Additionally, you need to keep proportions to always nearby units, for example, wagons and trains have to be proportional. Remember, objects with graphics size limitations have different proportions in different directions, you have follow them.

A useful thing, that can help you, is a scale. When you know the size of the object, you draw, you can select the best scale and draw elements in it. It makes the graphics look right. For long vehicles I use 3.3 pixels per meter scale. For diagonal view I use the factor of 0.(6) for 0X projection and 0.(3) for 0Y projection. Zoom uses 2.5 pixels per meter, but traces it bad (for example, 12 meter MAZ-103 lost 3 pixels in horizontal direction). Be careful. Michael Blunk uses 1.58 px/m scale for DB set trains in horizontal direction, because the trains graphics limitations. In perspective view he uses 1.333 ratio (that has to be 1.4 by ISO, but due TTD limitation it is not).

Now, when you've chosen the size of you graphics, draw the simple dimensional box to fit your graphics in. Fill it with the primary colors to specify the right colors allocation. If your object consists of several parts, make the base blocks for all of them. It can be also a cylinder, sphere ore some other geometrical object. It is required to make you place your object better.

The second step is to paint your blank into the real object. You can draw over the blank or cut parts of the existing graphics and put them over the blank - up to you. Usually I draw the side views and the front and background views (without the roof and perspective). Than I use the macros to make a perspective view from them as second level blank for diagonal views. Than I add the roof to the sides, front and back views. Than I fix the blank for diagonal views, and add the roof to them. Read more about drawing textures.

Now you have to make your graphics nice. You have to put shades, add the effects, the small decoration elements (stickers, inscriptions, lightings). Make you graphics shining.

If you have the independent graphics, you work is done. But if your graphics is part of picture, you need to check it with the other. In most cases you'll need to fix it a little for better conformity of the graphics and a good graphics balance.