The best way ti increase your milk production is
Nursing your baby often. …
Nurse your baby at least 15 minutes at each breast. …
Gently massage breast before and during feedings.
Use relaxation techniques to reduce stress and promote the flow of breast milk.
Provide skin to skin time with your baby for about 20 minutes after feeds.
And drink & eat well

Taking warm showers is meant to stimulate milk production.

Milk production is a demand & supply process. If you need to increase milk supply, it’s important to understand how milk is made – understanding this will help you to do the right things to increase production.
To speed milk production and increase overall milk supply, the key is to remove more milk from the breast and to do this frequently, so that less milk accumulates in the breast between feedings.
Make sure that baby is nursing efficiently. This is the “remove more milk” part of increasing milk production. If milk is not effectively removed from the breast, then mom’s milk supply decreases. If positioning and latch are “off” then baby is probably not transferring milk efficiently. A sleepy baby, use of nipple shields or various health or anatomical problems in baby can also interfere with baby’s ability to transfer milk. For a baby who is not nursing efficiently, trying to adequately empty milk from the breast is like trying to empty a swimming pool through a drinking straw – it can take forever. Inefficient milk transfer can lead to baby not getting enough milk or needing to nurse almost constantly to get enough milk. If baby is not transferring milk well, then it is important for mom to express milk after and/or between nursings to maintain milk supply while the breastfeeding problems are being addressed.
Nurse frequently, and for as long as your baby is actively nursing. Remember – you want to remove more milk from the breasts and do this frequently. If baby is having weight gain problems, aim to nurse at least every 1.5-2 hours during the day and at least every 3 hours at night.
Take a nursing vacation. Take baby to bed with you for 2-3 days, and do nothing but nurse (frequently!) and rest (well, you can eat too!).
Offer both sides at each feeding. Let baby finish the first side, then offer the second side.
Switch nurse. Switch sides 3 or more times during each feeding, every time that baby falls asleep, switches to “comfort” sucking, or loses interest. Use each side at least twice per feeding. Use breast compression to keep baby feeding longer. For good instructions on how to do this, see Dr. Jack Newman’s Protocol to manage breastmilk intake. This can be particularly helpful for sleepy or distractible babies.
Avoid pacifiers and bottles when possible. All of baby’s sucking needs should be met at the breast (see above). If a temporary supplement is medically required, it can be given with a nursing supplementer or by spoon, cup or dropper (see Alternative Feeding Methods).
Give baby only breastmilk. Avoid all solids, water, and formula if baby is younger than six months, and consider decreasing solids if baby is older. If you are using more than a few ounces of formula per day, wean from the supplements gradually to “challenge” your breasts to produce more milk.
Take care of mom. Rest. Sleep when baby sleeps. Relax. Drink liquids to thirst (don’t force liquids – drinking extra water does not increase supply), and eat a reasonably well-balanced diet.
Consider pumping. Adding pumping sessions after or between nursing sessions can be very helpful – pumping is very important when baby is not nursing efficiently or frequently enough, and can speed things up in all situations. Your aim in pumping is to remove more milk from the breasts and/or to increase frequency of breast emptying. When pumping to increase milk supply, to ensure that the pump removes an optimum amount of milk from the breast, keep pumping for 2-5 minutes after the last drops of milk. However, adding even a short pumping session (increasing frequency but perhaps not removing milk thoroughly) is helpful.
Consider a galactagogue. A substance (herb, prescription medication, etc.) that increases milk supply is called a galactagogue. Some of the most commonly used herbal galactagogues are fenugreek, blessed thistle, and alfalfa.

Brewers yeast and oats are meant to help boost your supply.