By Allah's will the best to stop black magic is the recite of last three sourah (ikhlass, falaq and Nass), beside reciting the sourah of Baqara in a house at day/night will prevent the shayateen from entering it for 3 days/night.. Sourah el safaat is very powerful.. and reading ayat el kursi is very important.
du'aa for general success is; 1) "elhamdoulellah" = thanks and praising are to Allah is the best du'aa. (if you are pleased with Allah's decree He will increase to you from the good.. and notice that all the matters of the believers are good and from Allah; so if something good happened he is thankful and if (it seems) bad he will be patient.. indeed; many things we might detest while Allah made in it a lot of good.. and how many things that we hate while it is good for us, and how many things that we like while it is bad for us.. if we really know. (may Allah show you the good in any matter that seems bad for you).. and truly as Allah said that with and after the hardship there is ease.
2)Astaghferullah= I ask Allah's forgiveness(to delete my sin, to remove the veils hiding me from His light), (asking Allah's forgiveness is the key word for all the good)
3) Allahumma Salli 3ala sayidinaaa Muhammad el nabey el ommey wa 3ala alihi wa sa7bihi wa sallam (as Allah chose prophet Muhammad as a messenger of the light of Allah to us it is important to receive Allah's light through him salla Allahou 3alayhi wa sallam) as Allah told us that He and the angels are doing salah on the prophet and He ask us the believers to do salah on him. and it is considered du'aa for us.
4) la 7awla wala qowwata ella b-Ellah. (no power nor circumstance but by Allah) it is a jewel from jannah.. and it is the total submission and surrendering to Allah's will/acts.
Rabbana Atena fid-dounya hassana, wa fil Akherati hassana, we qena azab an-naar.
(O our Lord, bestow a good on us in the world, and bestow a good on us in the End/last, and avoid us from the torment of Hell.
Rabb eghfer li wa er7amni wa ehdeni wa 3afeni wa erzoqni (o Allah forgive and have mercy on me, guide me, provide me and pardon/sound/protect me)
tabarakta ya nour al anwar, nawwar qalbi b-nouri ma3rifatika ya Allah ya Nour ya 7aqq ya Moubeen
(blesses You who is the light of the lights; enlighten my heart with the light of knowing You, O Allah, O (you who is) Light, O (You who is) Tuth, O (you who is) Clear.
May Allah do not prevent us from His mercy in this world nor in our graves nor in the last day.. we depend on nothing else except His mercy.
Good luck and Salamou alaikum