Splashing pupil premium cash on reducing class sizes, introducing school uniforms or after-school clubs are among the least effective ways to improve results, research published this week suggests.
According to the Sutton Trust charity, which works to improve educational opportunities for disadvantaged children, head-teachers should not spend additional money they are given to boost the performance of their poorest pupils on high-cost methods, such as smaller class sizes.
Instead, schools should try to get best value for their money by investing in low-cost approaches, such as ensuring their teachers provide quicker and more effective feedback to their pupils.
And to help schools spend their new cash more wisely, a pupil premium toolkit has been developed by academics at Durham University, providing a Which-style guide to give heads and their teachers the best advice on where to spend their money.
Steve Higgins, professor of education at Durham and lead author of the guide, said reducing class sizes only works if the pupil numbers can be brought down to as few as 15.
"Unless the teacher changes what they are doing, having four or five less students really won't make that much of a difference. If you go down to 15, then you can offer a more personalised learning," Professor Higgins said.
"With uniforms, the evidence shows a school with blazers, boaters and badges is just as likely to be unsuccessful as it is successful. It is the outward sign of discipline and the school's ethos but it is the symbol of these measures, not the causal effect."
This September, schools will for the first time be given a pupil premium - an additional pot of money based on the number of students they have on free school meals (FSM).
For every FSM pupil a school will be given #163;430 of additional cash. By 201415 the Government has pledged that it will provide #163;2.5 billion in pupil premium funding overall.
Sir Peter Lampl, chairman of the Sutton Trust, said: "The key to improving the attainment of disadvantaged pupils is not necessarily how much money is spent in schools, but how much is spent on what is proven to work in the classroom."
As well as better feedback, listed among the best approaches in the guide are encouraging students to think about their own learning strategies, and to promote more peer learning in the classroom.
But Brian Lightman, general secretary of the Association of School and College Leaders, said it was up to schools to make their own decisions when it came to how best to spend the pupil premium.
"The Government was absolutely right when it decided not to prescribe how schools should spend their money, as different schools have different needs," Mr Lightman said.
"Giving fast and effective feedback is just good teaching and all the best teachers should be doing it. Heads will always want to refer to best practise, but at the moment the amount of money is very, very small."
The results of the guide are at odds with the views of many teachers if a survey, also by the Sutton Trust, is anything to go by.
According to the poll, nearly three-quarters (73 per cent) of teachers said reducing class sizes was among their top three priorities when it came to spending pupil premium money.
Likewise, the guide claims that hiring more teaching assistants would offer little poor value for money, but nearly half of teachers would be in their top three choices.