Amina Inloes, Amina Inloes is originally from the US and has a PhD in Islamic Studies from the University of Exeter on Shi'a hadith. She is the program leader for the MA Islamic Studies program at the... Answer updated 1 month ago

Here are a few narrations on this topic:

Imam al-Sadiq (A) said, “The things which enter a person’s grave are ritual prayer, fasting, hajj, charity, good deeds, supplication, and its reward is written for those who do them and for the deceased.” (Man la yahduruhu al-faqih)

Imam al-Sadiq (A) said, “Whoever of the Muslims does a good deed for a deceased person, God will double his reward and benefit through it the deceased” (Bihar al-Anwar citing Uddat al-Da’i)

It is related that a man came to the Prophet (S) and asked, “My mother has died. Will it benefit her if I give charity on her behalf?” He said, “Yes.” (Musnad Ahmad)

Apart from Wahhabis who object to this because they see everything as bid'ah, it is hard to see the objection to this since if one is doing something good in the hopes that it would benefit the deceased, at least one is doing something good and beneficial. 

Maybe some people might object because some things are done for esaal-e-sawab which are not overly beneficial in the present time, for instance, printing Qur'ans and distributing them in an area where Qur'ans are easily accessible. This would have been very beneficial in earlier centuries but today because printing is cheap, it often is not the most beneficial thing to do even if it is meaningful, or sometimes things could even be wasteful. So it is good to think about what is most beneficial, and I am sure the deceased appreciate being remembered in a good way!