Reiki can be combined with any other therapy to compliment and deepen healing. Firstly, explain to your client, what it is you wish to do. Get permission to add Reiki in with any other healing methods that your clients might be after. 

For NLP and hypnosis, Reiki can help clients relax more deeply which in turn, can allow for the suggestions from NLP and hypnosis to have a more profound effect.

Running Reiki while giving reflexology, kinesiology, mirimiri, or massage can also be very beneficial for the client and for yourself as the channel. This can connect you more deeply with messages that you could receive from your clients energy field, giving the session a more profound healing touch.

Crystal healing works exceptionally well with Reiki. Simply add crystals to the clients body as you are going along. Use your intuition as to which crystal should be placed where or simply use chakra colours.

For example: a red crystal for the root chakra, orange for sacral, yellow for solar plexus, green or pink for heart, blue for throat, purple for third eye and clear or white for crown. 

Sound therapy can also be incorporated nicely with a Reiki session. Rain sticks and drumming can deepen your clients healing even further. 

To learn more about any of these other modalities, simply do a search in your area and go with what resonates with you.