This is a recipe I have used a few times.... you may need to adjust quantities to suit individual tastes.
1 750ml bottle decent aged rum
1 vanilla bean, split lengthwise
3 whole cloves
1 cinnamon stick, broken into pieces
5 whole allspice berries
5 whole black peppercorns
1/2 piece star anise
1/8 tsp fresh-grated nutmeg
3 quarter-size pieces fresh ginger
2 3-inch strips fresh orange zest, white pith removed
Procedure
Combine everything in a large jar and seal. Keep in a cool, dark place for a couple of days, shaking it once a day to distribute the ingredients. Start tasting it after 48 hours; adjust ingredients if necessary, and once you feel it’s done (probably no longer than 4 days altogether), strain and bottle.
Cheers
Icarus