The use of filters is very personal. One thing has changed in the last 40 years - way back then, you really did need to use a yellow filter to get "correct" tone rendering with b+w filters outdoors, skies would otherwise be too light or even print white. With modern films you do not need to do this, the color rendition is balanced. Filters do, however, add drama and a personal viewpoint. Some people always use red for landscapes, others always orange. Personally, I find the rendition with yellow too insipid, red excessive, orange about right except that it lightens red too much (words on signs, etc.) so the compromise I choose is a 2x yellow/green filter, which I use for all shots for consistency, even though the difference between this and yellow may well be slight. Fundamentally yellow passes green and red, absorbs blue, while yellow/green passes green and less red. For studio work, I would shoot people with no filter if they have great skin, otherwise I might use a yellow.

What Lars Bergquist says is fundamentally right, like many amateur experts he is a little over-emphatic. The choice of a filter is really down to personal taste. If you have a lot of filters to choose from, you really need to do some tests (just 4 shots of the same scene with different filters would be enough).