Use relevant hashtags (#) on your posts. So far, I have not heard of the perfect hashtag trick. Yet you should preferably use ´small´ hashtags.
What do I mean by ´small´ hashtags? Well go to your post and act like you want to add a comment, using hashtags. If you add #travel, you might see this is a ´big´ hashtag, over 10 million people have used this before. So you might want to use hashtags with a smaller amount of numbers, that people only have used 1000 times.
Reason for this: is if the hashtag is not that often used and people look at it, your photo might pop up faster, than within all those 1 million other photos on the other hashtag. It will be more difficult to stand out. If you do, congrats!
Another thing you can do is create your own hashtag. I have created #aborntraveller and #a_born_traveller, so whenever someone searches for those hashtags, my photos will mostly be visible. I recommend you do the same!
The last thing about hashtags is the amount of what you should use. Some say you should use between 13-20 hashtags on your post, some say all 30. I mix it up as I am still not sure what Instagram expects from us.