One of the best books translated into English is the World of the Jinn by Dr. Umar Ashqar. In it he writes about many of the tactics used by the Shayaateen (devils) to turn mankind away from the worship of Allah.
This is from the promise of Shaytan (may Allah curse him) to Allah when he said : "O my Lord! because Thou hast put me in the wrong, I will make wrong fair-seeming to them on the earth, and I will put them all in the wrong!
And the greatest wrong that a person can do is the one sin that Allah does not forgive; to call upon someone other than Allah.
"Indeed, shirk (to make worship other than Allah) is the greatest wrongdoing" 31:13
The devils are tricky and that is why Allah warned us against them. In reality they are not powerful at all. In fact, they are jealous of human being and are very weak creatures.
Because they are weak the jinn get very proud when human beings who are stronger and more honored by Allah obey them instead of Allah the Almighty.
Strength of faith prevents the jinn from harming a person, so much so that if they were to fight, the one who has faith would win.
Abd-Allaah ibn Mas’ood (may Allaah be pleased with him) said: “A man from among the Companions of Muhammad met a man from among the jinn. They wrestled, and the human knocked down the jinn. The human said to him, ‘You look small and skinny to me, and your forearms look like the front paws of a dog. Do all the jinn look like this, or only you?’ He said, ‘No, by Allaah, among them I am strong... reported by Ad daarami
So the best way to gaurd yourself against them is with Islam. Even though you cannot see the Jinn you believe in them now based upon "vague and hard to interpretate" experiences.
Don't you have more clear evidence that Allah is the Creator of you and me when we did not create ourselves and we don't have the power to create anything?
Our existence is a sign of Allah. And look at the way that the universe is ordered? That is a sign of great power and planning.
And even this comment. You cannot see me nor can I see you. But you can see my writing and know from this I exist. We know from the Book of Allah that He exists because in the Book is Perfect guidance, insight, and truth that could only come from the Lord of all that exists.
Take shahaadah. Say that you bear witness that none has the right to be worshipped except Allah and you bear witness that Muhammad is his slave and messenger.
Then seek refuge in Allah. Because the One who can protect you from jinn you cannot see, is the One who the jinn fear though they can not see.