I'd assume that it's pretty much like saving up for anything. Have an extra coin bank and throw something in whenever you see some leftover change, perhaps stay on track with other purchases and think of if you might not pass on the occasional one to rather put that into your dream funds and simply be patient in the meanwhile. ^_^

Banks used to have "vacation clubs" where you could choose an amount and every week they would deduct it from your bank account and at the end of the year you could then have access to the savings. The best way would to ask your bank if they have something like that. Or open up a savings account and have an automatic deposit into it until you reach your goal.