Answered by Shaykh Faraz Rabbani
When ever i have done wudu, i washed my hands first, which is sunnah, then when it came to washing my arms, i washed from the wristbone to the elbow.
For sometime i have become troublesome and doubtful about whether my wudu is valid. By reading the books of fiqh, i learned that one must wash from the fingertips to th elbow, not wristbone to the elbow.
I however thought as i wash my hands in the begining, this would be sufficiant.
I am beginging to worry now if what i did was wrong and if any of my salah or worship have ever being valid, as i may not have washed my arm as i should have, so my wudu was never complete, and washing the hands in the begining doesnt count.
please advise, i am very worried.
waalaikum salam

Walaikum assalam wa rahmatullah,
I pray that this finds you well, and in the best of health and spirits. May Allah grant you all good and success in this life and the next.
If you washed your hands at the beginning of wudu, and then only washed from yours wrists when washing your arms, your wudu would be valid–as the initial sunna of washing hands fulfills the obligation related to the hands. [ Ibn Abidin, Radd al-Muhtar ]
At the same time, it is best when washing the arms to wash them from the fingertips.
And Allah alone gives success. Faraz Rabbani