Nice tip! We have a tree that's been growing almost half way to out entrance for years and we have not been able to do a thing about it, every time we chopped it down it came back... lets try this for a change.
1) Aerating once a year will do wonders for your garden although you can live without it.
2) I will recommend that you rent an aerator rather then buying one, there is a tool rental at best buy that rents aerators as well I think.
3) Its not necessary to apply sand afterwords.
hope this...