I drink very weak english tea - two to three cups a day, no coffee obv. I live in germany and cant get caffeine free english tea here. I cant stomach rooibos tea (i think it is a marmite type tea). Peppermint tea - lots. Be careful with Camomile tea actually, it can be harmful in large doses (herbs can be very powerful), obv. do not touch rasberry leaf tea - this is used to bring on labour, be careful with spices like star anise, too much ginger, nettle etc. Basically, peppermint, no problem (although when breast feeding can dry milk up a bit), rooibos too, decaff english, etc - see the link and I pasted a bit below for info. Good old slice of lemon and honey also great.
www.babycenter.com/0_herbal-teas-during-pregnancy_3537.bc
Herbs that may cause problems include anise, ginger, lime blossom, rose hip, catnip, chamomile, comfrey, ephedra (called ma huang in traditional Chinese medicine and banned in the U.S. since 2004), European mistletoe, hibiscus, horehound, Labrador, lemongrass, licorice root, mugwort, pennyroyal, raspberry leaf, rosemary, sage, sassafras, stinging nettle leaf, vetiver, and yarrow.