A few examples of these are:

Abu Hurairah radhiAllahu anhu would do masah (wiping) of his neck during wudhu. Umar radhiAllahu anhu would put water in his eyes and do masah of the ears, Abdullah Ibn Umar radhiAllahu considered it virtuous to walk along the same routes which the Prophet [May Allah bless Him and grant Him peace] used in his lifetime also to stop where the Prophet [May Allah bless Him and grant Him peace] stopped, and to perform wudhu where (RasoolAllah Sallallahu' alaihi wa sallam) performed it. Abdullah Ibn Umar would also touch with his hands the places where (Rasoolallah Sallallahu'alaihi wa sallam) sat to obtain Baraka (blessings). 

[Qaydah Jaleelah page 223 by Hafidhh Ibn Taymiyyah]

All of this is evidence in support of the fact it is permitted to do something not done by the Prophet [May Allah bless Him and grant Him peace] so long as it does not oppose the Sunnah and is intended for reward alone. As this was the practice of the Sahaba radhiAllahu anhum. 

The objection, which could arise, is that: 'The Companions had the authority to start something new but we do not.' 

Firstly: Not all the things mentioned earlier were started by the Companions.

Secondly, Hafidhh Ibn Taimiyyah writes: "Apart from the Prophet [May Allah bless Him and grant Him peace] no one has the right to introduce anything new to the Deen (Religion) and then call it Sunnah, the Khulafa Rashideen followed the Sunnah, therefore their way is called the way of the Prophet [May Allah bless Him and grant Him peace]. Wajib is only what Allah has made Wajib and Haraam is only that which Allah and his Messenger has forbidden, the authority of classifying Mustahab (Desirable), Mubaah (permissible), and Makrooh (Disliked), is with the Prophet [May Allah bless Him and grant Him peace] alone. No others have such authority". He continues by saying, "The majority of Scholars do not consider the (above) practice of Abdullah Ibn Umar to be permitted" ["Hafidhh Ibn Taimiyyah]

[Qaydah Jaleelah chap action of Sihabah by Hafidhh Ibn Taymiyyah] 

According to Hafidhh Ibn Taymiyyahs statement we can see that the sunnah can only be something that was practised by the Prophet not by anyone else. Some people consider something to be Bid’ah, which was not practised by the Prophet, or His Companions. According to the above statement they cannot say this as the Prophet [May Allah bless him and grant him peace] only had such Authority to do so.

In the following pages we will discuss some of the issues, which are considered as ‘Bidah’ by some of the Muslims.