Refer good architecture daily - one only learns when one has a very good exposure to good design. Today, it is extremely easy to see good design and architecture, especially with some really wonderful websites and blogs on each and every topic. I often wonder at the musicians who practice daily to fine tune their art, even the dancers who spent an enormous amount of time perfecting their craft. But we architects don't do anything remotely close to that. Most of us think that once we get out of architecture school, we are masters , with everything at our fingertips. However, if one were to look at the really successful architects, you would see that they are constantly learning, constantly fine tuning their knowledge and craft. They are continuously seeing good architecture done around the world. For students of architecture, the easiest way would be to constantly refer architecture websites, especially those like archdaily, which constantly uploads new projects.
Be a voracious reader - not just architecture, but more so of fiction. Reading broadens ones perspective, it expands your mind. New ideas are formed, one becomes aware of newer developments, about different ways of life, about different thought processes. An architect needs to have a fine understanding of the society and the world around, to understand people and cultures. Reading helps one in that. It gives you depth in your designs and responses. Along with fiction, reading newspaper I'd another essential activity for an aspiring architect. You need to be aware of the world around you, about current affairs even about politics, for you to converse and advise your clients appropriately. For this, daily newspaper reading is an essential habit to be developed.
Sketch daily - sketching is an essential form of communication for any architect to convey his / her ideas. By sketching, it is not artistic 3dimensional sketching that is required, but more of good simple sketches to explain your ideas
Photograph daily - as an architect, it is important that one learns various aspects of photography like framing, composing, playing with light, scale, proportions, layers etc, which are all relevant for an architect. In today's world, everyone is a photographer. Smartphone cameras have evolved tremendously over the years to reach an almost professional quality. As an architect, it is also important to document what one sees around, as future reference. Photography helps you to create a very good databank, which will also serve as a ready source of reference material.