How do you reduce the appearance of wrinkles?

Depends on cause. Depends on what kind of wrinkle: there are dynamic lines caused by facial expression which can be helped by botox, there are deep lines caused by smiling which can be helped by fillers, there are textural irregularities and surface wrinkles which can be helped by resurfacing procedures such as fractional co2. Sleep lines (caused by sleeping on your face) can be helped by sleeping on your back.
Multiple options. How wrinkles are treated depends on where they are, how severe they are and how the relate to facial movement. Treatments with Botox or Dysport will reduce those wrinkles caused by facial movement- such as crows feet and frown lines. More established wrinkles may need and injectable filler like Restylane (dermal fillers) or perhaps skin resurfacing with a laser. Consult with your doctor.
Several Options. Dynamic lines produced in the upper part of the face are best treated & prevented with Botox first. Lines that are more static are best approached with laser ablation and chemical peels. Deeper furrows can be relieved with dermal fillers like juvederm. Skincare at home with Retin-A can help to prevent the progression of lines. Protect your skin with spf. Hope this helps!
Reduce wrinkes. Botox for muscle active wrinkles, filler and resurfacing with fraxel laser, portrait plasma devices, dermabrasion, for lines at rest from sundamage, smoking, age, etc. Topical moisturizers, antioxidants and most importantly, sunscreen use and sun avoidance .