BVE CROATIA VALLIS AUREA
How to make good texture for BVE by correcting perspective!
Good textures makes every BVE route more realistic. Therefore, it is best to use texture from real life, from photographies.
Of course, keep in mind copyright of photography. The best solution is to have your own. That way you can try yourself as
photographer as well. It is best because you already know what material you need and you depend only about yourself.
1. There are many graphic editors on the market which feature perspective correction, but I am recommending best freeware graphic editor:
GIMP.. I personally prefer GIMPShop.
2. Resize your photo to 800*600 (or less) pixels and save it in JPEG format. Then open it in GIMP.

3. Right-click with mouse on the image. The windows will appear, click TOOLS then TRANSFORM then PERSPECTIVE.

4. Note red marked Perspective section on the left. It is very important to get this setting. Try to stretch the grid on desired texture portion. Be careful, you can enlarge it to help yourself.

5. Sadly, I wasn't so careful (you can see that lower left grid line is not the same as the green line on the car). That's why it is important to have it punctual.

6. Save the image in acceptable size (512*64 or something like that) and save it as BMP file. You can leave it in enlarged size and edit it and that resize it, it is up to you.
CONCLUSION:
By this method you can get almost any texture (trees, buildings, tunnel portals, track ties...). Of course, in lots of cases, you have to make transparency color, so keep it in mind. It is also desired to save it as 8-bit textures because it makes better performance without high frame rates.
The author of famous Joetsu BVE lines also wrote very interesting article about GIMP editing. Feel free to read it:
tranlsated link (with Excite on-line translation)
I hope I have helped you. Enjoy, best regards.