'Shaytan said: “Because You have put me in error, I will surely sit in wait for them on Your straight path. Then I will come to them from before them and from behind them and on their right and on their left, and You will not find most of them grateful [to You]".' - Q7:16-17
There are 7 major phases with with Shaytan attempts to take us away from the straight path.
1. The phase of disbelief in Allah.
This initial phase is one in which Shaytan attempts to make the person a kaafir (one who has been given the message but chooses to reject it). This leads to the person associating partners with Allah (shirk). If Shaytan is successful in misleading the slave in this phase, he has accomplished his goal. If the slave succeeds, and survives this phase, Shaytan would look to the next phase.
2. The phase of religious innovation.
At this phase, Shaytan attempts to make the person follow innovations in the deen. Shaytan enjoys that one succumbs in this phase, for Bid’ah (religious innovation) conflicts with the Deen and compels one to reject it. Furthermore, the one who observes innovated religious practices would not repent from his actions; rather, he would invite more people to his Bid’ah. Minor Bid’ah practices would lead one to observing major ones; which in turn leads to the person exiting the fold of Islam. If a person succeeds and survives this phase by adhering to the Sunnah, Shaytan would move to the next phase.
3. Major sins (al-Kabaair).
The Prophet (SAW) said: “I was with two angels and Jibreel (as). I saw some people in a big pit of fire. They were completely naked, and the fire would blaze while their bodies were on top of it and they would be screaming. I asked Jibreel, ‘Who are these people?’ and he replied, ‘These are the people of fornication.’ Then I saw a person in the middle of a river made of blood. This person was trying to get out of the river and come to the shore. As he was coming he would be hit in the face with stones, and it was the blood coming from his head that had made this river of blood. I asked Jibreel who the man was and he said, ‘The person of ribaa (interest).’ Then I saw a person who was sitting and a large stone was dropped on his head. The stone would return and his head would come back to normal. As soon as his head returned to normal, the stone would be dropped on his head once again. I asked Jibreel who he was and he said, ‘This is the person who has the Qur’an and doesn’t pray with it in the night.’ Then I saw some people whose lips and tongues were being cut with scissors, and as soon as their lips and tongues were cut they would come back to normal. I asked who those people were, and Jibreel said, ‘They are the people who backbite.’” - Bukhari
The major sin are described in this hadith and the punishment is one we strive to avoid. Shaytan realizes at this point that he can't make the person a kaafir or practice Bid'ah so he leads him on the path of punishment by pushing us towards the major sins.
4. Minor sins (al-Saghaair).
Shaytan would compel a person to belittle sins and convince the individual that there is no harm in doing minor sins, until it becomes a habit. The person who has done a major sin, and has repented and is fearful of what he has done, would be better off than him; for regularly doing a minor sin would change it to a major sin!
Rasulullaah (SAW) said: “Beware of minor sins; its likeness is like a people who stopped over in a valley, they spread out in search of fire wood, and each brought a stick; they were able to make a fire and cooked their bread. Whenever a person practices a minor sin regularly it would destroy him.” - Ahmed
If the slave succeeds and survives this phase, by repenting continuously to Allah and observing righteous deeds, Shaytan would move to the next phase.
5. Distracting an individual in order to keep him away from worshipping Allah.
Al-mubaahat (permissible things) are seemly innocent activities that are as the name suggests permitted. It could range from a simple conversation to everyday activities such as shopping or watching tv. Activities which should ideally take minutes becoming an all day affair. The issue is that we then become indulged in these permissible activities that we forget our solat and the remembrance of Allah. Anything that we do without reward or benefit is a victory for Shaytan, hence as muslims we must avoid this trick by being proactive in our worship. If the slave succeeds and survives this phase by understanding the greatness of the acts of worship, Shaytan would move on to the next phase.
6. The phase of busying the slave with deeds which are less rewarding.
So, at this point Shaytan realizes that your faith is strong enough and that you will strive to do good, so he encourages the slave to observe certain acts of worship and ignore others. He would trick you into picking the act with the least reward. In order to avoid this trick, we need to understand fiqh al-awliyaat (the fiqh of priorities) and know that the best act of worship is dependent on the time and place a Muslim finds himself. What will bring the most benefit and reward according to its time and place is what you should do.
7. Any means necessary.
The last thing Shaytan does, if he can’t get you to fall into any of the first six traps, is an all out attack with jinn. The jinn goes to others and causes them not to like you. This leads to people speaking badly of you, trying to cause you to destroy your reputation and cause you to waver from the deen. These attacks can increase in intensity depending on the level of one's iman.
For further reading; I recommend Madaarij as-Saalikeen by ibn Qayyeem al-Jawziyyah - Available on Amazon and if you are lucky enough at your local Islamic bookshop.