Some pilgrims bypass the designated Station of Ihram on their route without either being in Ihram or entering into Ihram there, proceeding until they reach Jeddah or some other place within the precincts of the Stations, at which they enter into Ihram.
This is against the command of Allah’s Messenger (peace be on him), which stipulates that every pilgrim should enter into Ihram at the Station of Ihram which lies on his route.
If this happens to someone, he must either go back to the Station of Ihram lying on his route and there enter into Ihram, or he must make expiation by sacrificing a sheep in Makkah and feeding all its meat to the poor.
This applies to all pilgrims regardless of whether one passes the Station of Ihram by air, by sea or by land.
If one did not pass through one of the five designated Stations of Ihram he should enter into Ihram at a point which is nearest to the Station of Ihram on his route.
Starting the Tawaf at some point other than the site of the Black Stone, while it is obligatory to begin tawaf from the Black Stone.
Doing ramal (i.e., taking quick short steps) during all seven circuits while ramal is to be done only during the first three of the Tawaf of Arrival (tawaf al-qudum).
Accelerating one’s pace throughout the entire distance between the two hills. The sunnah is to accelerate one’s pace only between the two green posts, while walking at normal pace the remainder of the way.
Some pilgrims camp outside the boundaries of ‘Arafat and remain there until the sun has set; then they depart for Muzdalifah without standing at ‘Arafat properly.
This is a serious error which invalidates their Hajj since standing in Arafat is the essence of Hajj, and it is obligatory to be within its boundaries and not outside them, if it is not easy to do that, they may enter before sunset and remain there until sunset.
It is quite acceptable to stand in Arafat during the night of sacrifice in particular.
Pebbels should be size of bean, where as some pilgrim pick the large size pebels and throw with full force which bounce and some time fall back on the near by other worshipers.
So it is advised to avoid to this practice.
Throwing all the pebbles at one time is an error. Scholars have said that this would be counted as only one throw.
Appointing a proxy to throw the pebbles, simply due to fear of the crowds or of hardship, while one is capable of doing it himself.
Only sick or weak individuals are permitted to have a proxy for this act.
Crowding and fighting with others at the Pillars while throwing the pebbles is not permissible.
What is prescribed is to be gentle and to throw the pebbles without hurting anyone as much as possible.