While you can create a charitable legacy through several different methods, donor advised funds are gaining in popularity as a good way to do so, according to the Wills, Trusts & Estates Prof Blog in "The Rise of Donor Advised Funds."
With a donor advised fund, you can invest money now that will be used for charity later. The donor gets an immediate tax benefit and can invest however much he or she wants.
Contributions can be made over time or all at once, whichever is more beneficial. The donor does not have to actually advise how the funds are invested, if not interested in doing so. However, they can, if they are interested.
An estate planning attorney can guide you in creating a charitable legacy that fits your interests.
Reference: Wills, Trusts & Estates Prof Blog (May 18, 2017) "The Rise of Donor Advised Funds."