Over the years many people have tried to make their own Slalom poles but they seldom perform anything like as well as FIS approved flex poles which must be made to a very specific standard and therefore perform in a very 'repeatable' manner. (specification, list of homologated manufacturers Etc. on FIS website)
Standard ski slalom poles come in red and blue designed to be high-contrast against a white background. Some manufacturers offer the same thing in bright orange or other colours which are far better when used against a dark background such as grass or dirt.
Standard ski slalom poles come with a variety of ground fixing options; generally straight, screw or brush, none of which are ideal directly in turf or dirt as they tend to become dislodged after some use. The favoured solution is to make locally some metal ground-inserts which are solidly dug into the ground in advance of the event in pre-prepared positions into which the screw type of slalom pole can be quickly and firmly inserted when required.