How do I create more contrast in my black and white photography?

Lens filters are a good way to do this. The primary ones for landscape would be yellow, orange, and red. Yellow adding a little contrast, orange adding more, and red adding a lot of contrast. Meter and take the photo with the filter on. Cheap ones go for around $10 each.

As a professional photographer, MFA in Photography, and photo instructor, I have to take issue with the first responder's answer. He told how how to decrease contrast. Over exposing and underdeveloping will yield more shadow detail while controlling the highlights, in fact contracting the contrast. This is called pulling the film. To expand the contrast, you should UNDEREXPOSE the film and OVERDEVELOP it. This is called pushing the film. What this will do is turn the shadow areas more black and blow out the highlights (white) thereby increasing the contrast range. So, the easiest way to accomplish this is to set your meter 1 stop faster than the actual film speed, i.e. 100 speed is rated 200, 200 is rated 400 ect. I suspect, from many years of teaching beginners, that you have more than one problem here. First, if you want a high contrast shot, shoot during the middle of the day when the light is very contrasty. Then, check your metering. Meter on the shadow areas, the midtones and the highlights. Figure out the range of stops by counting them, eg if the shadow reads 1/125 at ƒ4, the midtone at ƒ8 and the highlight (the sky perhaps?) ƒ22 you have a range of 6 stops. (4,5.6,8, 11, 16, 22-count on your fingers). Most good b/w films will record this nicely. Kodak tri-x at 200 (which is its true speed btw) will handle this nicely. Next, look at your developing. When the film is in the developer, you should agitate continuously for the first 30 seconds, then for 5 seconds every thirty seconds thereafter. And I don't mean a light swish, I mean shake the damn can. Agitation is necessary to get fresh developer in contact with the surface of the film - if you don't agitate vigorously or often enough, the film will come out flat (grey).Also be sure you are mixing the developer properly. Follow the directions-D76 is a great developer, cheap, and has been working well for generations. I use this in my classes, although I have been very happy with Ilford developers as well. The point is put enough in-FOLLOW THE DIRECTIONS TO THE LETTER. i find for many students this is the main problem. To enhance contrast, use contrast filters in both the shooting and printing stages. The first responder told you how to darken a sky slightly-an orange or red filter will do so dramatically. Your filters work like this: Each filter will lighten itself and the colors adjacent to it on the color wheel, and darken its opposite and the opposite's adjacent colors. This means yellow lightens itself, red and green, while darkening blue, cyan and magenta (the blue part of both). Red lightens itself, magenta and yellow, darkens green, blue and cyan. Green lightens itself, cyan and yellow, darkens red, magenta and to a lesser extent, blue. Also use a polarizer to cut out glare and slightly darken the sky. Always use a contrast filter when printing (start with a 21/2, increase as necessary.) Again, the dilution of your developer is critical, as is the temperature (68 degrees F). I prefer Dektol at 1:1 for high contrast, if I'm going for shock value Dektol straight is great. Ilford paper is better than Kodak (who stopped making b/w paper anyway.) Use Multigrade paper until you are very sure of what you are doing. Finally, you have to be consistent in how you meter, develop the film, and print the image. Once you find your filmspeed/development time combo (for tri x in D76 at 1:1 dilution, it can be anywhere from 12 to 14 minutes at 68 degrees) always use this ASA rating and development time/dilution. This can take some testing at various ASAs and development times. You expose for the shadows but develop for the highlights-ie make sure you develop long enough for highlight detail to come in. Next, when you print, you should ALWAYS leave the print in the developer with agitation (gentle but continuous) for 1.5 minutes (some ppl prefer 2 - again you have to test and again assuming Dektol at 1:1 - Dektol can be diluted all the way to 1:9) Printing is for the highlights so on your test strip, be sure to include them and set the time for them. Dodge the shadows if you need to. If the print is too flat (grey) increase the contrast filter. I highly recommend you read Ansel Adams' books The Camera, The Negative and The Print. Do that and you will love your results.