As a writer you need to be aware. This way you can pick up ideas and thoughts more easily or see or hear things that you could incorporate in what you write.
And although you may think, 'Ok, I will be more aware,' this is not always enough. You need to actually take in and note down what you see. Jot down your thoughts in a notebook or, if have one and are able, record your impressions on your MP3.
And in addition to noticing what may be going on around you, keep alert for writing possibilities and markets. You could see something interesting or amusing that could make a good filler or be made into an article or a magazine you could possible write for.
As a writer it is essential to be aware.
There are writing ideas and possibilities all around.
And as a final thought. Today, make an effort to be especially aware and to notice or think of something that could have some writing value for you and be sure to write it down.