More than a learning method, spacing deals with how to structure learning and when to learned it.
In order to remember better, the information should be repeated. But the mass repetition, meaning repeating right after another is less useful than repeating in the intervals.
The reason for this is in our brain. When we do mass repetition, we are recalling information from our short time memory. But if we let an interval pass, then we have to recall our information from long term memory.
At the same time, it stops the forgetting curve to keep falling, making the rise to the knowing status again.
For example, remembering the word in a foreign language. In order to remember the word, we could have read it 100 times today, along with the translation. Or we could read it once every day for 100 days. After 100 days, what word would be better remembered (if we take into account, that the 2 words were not encountered by random chance)?
The time of the interval is usually referenced as 10%-20% of the interval the information will be remembered.
For example, if trying to remember for a year, then the intervals would be about a month. If for a week, the interval would be 1 day.
There is also a concept if increasing the repetition. Since on the beggining, the information is new, it is repeated in shorter intervals. But with every correct retrieval, the interval gets longer.
The program that I am using and takes advantage of this fact is Anki. It uses SuperMemo algorithm number 2, and the parameters, like % of facts wanting to remember, can be adjusted.
If you want to control the system yourself, then you can simply schedule the learning, so there are intervals between learning time. Or try one of the systems like Anki or Mnemosyne? Or checking out the Leitner system, if not fan of the computers.