Creating and maintaining a brand is exactly the same as creating and maintaining relationships in our personal lives. It comes down to the same timeless truths such as our missions, goals, values and character. You need to clearly know what these are and also how to communicate them effectively to others in order to A: create the right first impression and B: keep the relationship alive over time. 
Strengths:
It’s always best to focus on your strengths in branding than to improve your weaknesses because strengths are what create differentiation and can be used to gain more market share.
Consistency:
The real elements of a brand are created in the market's mind through repeated personal experience, so it's absolutely vital that these experiences are consistent from one to the next. If they aren't, the brands' image becomes diluted and meaningless.
Emotions:
Always emphasize the emotions behind choosing your brand over another. Will it bring your customers security, prestige, envy, popularity or fulfillment? Apple has always done this in their marketing with regular-looking people using the products in everyday scenarios people can identify with. Make people love your brand, not like it.
Fans:
The biggest fans of your brand are usually heavily invested in it and can be powerful forces to help shape your brand for years to come. Meet with them regularly and get their feedback on your products, advertising, service etc. They will usually be very helpful and might just provide ideas to grow your business drastically. Make sure to reward them with special services such as a VIP card or lifetime discounts.
Change:
The only constant in life is change and brands are no different. To stay relevant one needs to constantly be updating and refreshing one's brand. Be like Madonna and re-invent yourself for the present market while staying true to what you believe and provide.
Tactics:
Businesses do not need to use every marketing channel available to them. This would drive any business crazy and is a surefire route to burnout. Use only the channels appropriate to your business and nothing more in the beginning. Then make sure you invest, refine and eventually dominate that space before adding any more.
Measure:
Most importantly of all, measure the effect your brand is having in your market. If more people are using you over competitor X, it means you're doing something right. As long as price is not your only competitive advantage, keep refining your brand until more and more people are using you, then you have a real brand people will trust for a long time.
In the beginning it was just about the business – now it’s about the brand. – Richard Branson