Choose a location you’d find interesting like a tropical jungle, a city, ancient ruins or a mountain. Create two characters who would have a good reason to go there and make them hate each other for some reason. Think what they’re looking for, or being chased by; then flip it part way through so that they run out of water, fall down a cliff, get chased by wolves etc.

Then do a google image search for ‘mountains’, ‘tropical jungle’ etc so you’ve got pictures to help with your descriptions. Think would it be hot, cold, jagged, etc? What objects would they have with them? Create an increasingly sinister mood and go into detail as they explore the landscape. 

Conjure up a situation that you find interesting – hunting wolves, looking for treasure, etc – then slowly build up tension as we start to realise that things are going wrong.

You will need
describing words, including interesting verb-choices
sensory language light/shade
sensory language general

Most importantly, you should constantly try to create a strong mood.

If this is a 1,000 word story, you need to spend time on description and not try to fill the space with millions of events, briefly described.