The vector > raster conversion is not as problematic as the opposite direction.
But you have to keep in mind, this process in irreversibla and you have to understand the process to ba able to choose the right parameters.

1. Resolution:
we have to choose as low resolution as it suitable for our final need. Increasing the resolution is enlarging the file size.

	300 dpi (file size: 75 KB)
	200 dpi (enlarged to the 300 dpi size) (file size: 38 KB)
	150 dpi (enlarged to the 300 dpi size) (file size: 26 KB)
	100 dpi (enlarged to the 300 dpi size) (file size: 15 KB)
	72 dpi (enlarged to the 300 dpi size) (file size: 9 KB)

2. Colour depth:
Decreasing the number of colours during the conversion in the raster file is slightly decreasing the file size.

3. File format:
Converting the vector information into a raster file we have to choose the proper file format (TIFF, BMP, JPG, GIF, PNG).
BMP - good in WIndows environment, relatively large file, but it is fast to open.
TIFF - the most professional format, very flexible, but not very small size.
GIF, JPG, PNG - lossy compression, suitable for the internet.