An important part of my photography gear to use on trips are filters for black and white film. I use both 4" square gelatin filters which drop into a slot on a lens shade as well as glass ones that screw into the lens. I use these primarily in reproducing a blue sky correctly to show clouds and in reproducing foliage greens light enough to appear natural.
For clouds I usually use an orange (#21), which is my favorite, and for foliage a light green (#11). Sometimes I use a yellow (#8) which alone gives proper sky, clouds and foliage renderings. Some of my friends have that yellow filter on their lens at all times. For a dramatic sky I sometimes use a light red (#23A) but not often. I also use a pola-screen that is adjustable and can darken a blue sky and also subdue oblique reflections from a variety of materials.
One must experiment with various filters and the pola-screen to see the effects on the ground glass and in the final print. It is a matter of personal preference on how one wants the image to appear in the final print. There are many more filters for black and white as well as for color. There are various shades of yellow, green and red as well as blue and others. Most good photography books have chapters on filters and what they do. Freestyle has these items in various sizes, shapes and forms for all cameras, so acquire some for your camera and go make photographs.