Answered by Shaykh Ilyas Patel
Can nails be cut in any order? Meaning, should we start with right hand and end with right hand (leaving right thumb for last), or does it not really matter?
Some scholars have put the order of clipping the nails into a poem:
Clip your nails with sunnah and etiquette
From its right then from the left (Shiratul-Islam)
It is mentioned in Fathul-Bari that Imam Ahmad has mentioned this method. Sharaf Damyati has reported from some scholars that whoever clips his nails without order he will have sore eyes. (Allama Hasan Shurunbulali, Maraqil-Falah Pg 429,430)
The following is the order to clip the finger nails:
First the index finger, followed by the forefinger, the ring finger and then the little finger.
First the little finger, followed by the ring finger, the forefinger, the index finger, the thumb and lastly the thumb of the right hand.
The following is the order to clip the toe nails:
One begins with the toe of the right foot and ends with the toe of the left foot.
And Allah alone gives success.