5 Attack, 5 Strength. Then 10 att. Then 10 Strength. 15 att. 15 str. 20 att. 20 str. 25 att. 30 str. (you will have better control at 25-30), and 30 att. 35 str. 35 att. 45 str., 40 att., 50 str. 45 att. 55 str. 50 att. (If you're looking to work str in a frenzied manner and then stop at attack, get Gmaul.
I suggest that you aim for five attack levels per 10+ from 50plus. There's no reason to have a 100% pure of 99 str and 50 hit since you will not hit. You can work on your range, defense and prayer, mage and range, if you want. The best is double comparitive. If you're seeking to eat something, I would not recommend making an undiluted.