This is a rather simple technique in theory, but it's one I would only recomend as a last effort at tuning, unless you build it into an application from the get go, it can be a real major pain to transition.

In some languages, such as Cobol, this sort of tuning has no benefit. While in languages like C (++, #, etc...) it will.

It basicaly involves moving all litterals in every peice of code, strings (especialy commonly reused strings), integers, numbers, dates, etc... into a Static Class usualy in a common class library. I usualy name that class, Constants in each project I do this with.

The benefit with this is if you say you have a lot of if (somehting.lenght > 0) logic thoughout your code, relpacing the literals 0 with Constants.Zero will eliminate many repeated allocations of that literal (and it's garbage collections), in that the allocations happen only one at the start of the application when it loads the class library or class, and lasts for the life of the running application.

The down side of this, is it may make code a bit more difficult to read for someone coming along after you.