Every one at some point or other suffers from creative block, be it artistic, at work, in the kitchen or just a feeling of inspirational void. It is usually fuelled by your own self doubts and can be quite depressing. It can sometimes be avoided or at least mitigated by a gentle shift in perception and attitude. Here are some of the tricks I have used or good advice that has been given to me that may help.

Change scale.

We are often attuned to a subject or style that may limit our perceptions. Looking "larger" or "smaller" can both increase our compositional tools and give us some stimulus to get out of a rut. Rather than shooting wide angle street scenes, try to pick out defining details or abstracts or go even wider/closer. This also applies to working in weather conditions or lighting that are not your norm or different compositional styles. My own limited landscape work is usually based on semi abstract details, close or distant. I rarely do a standard wide angle landscape shot, but if it occurs to me to try, they are often worth the effort.

Change style or subject.

Do something that you have never done before. If you usually use a tripod, go free hand and pick a subject that suits. If you are a landscape photographer, try some street (street landscape?) or portrait work. Obviously avoid forms of photography that you are not equipped for and those you are completely disinterested in, but hopefully there is another form, removed enough from your main passion, that is comfortable for you. I guarantee you will learn something from other styles that can be applied to your standard fare or at the very least you will appreciate your usual methods more. A sports shooter may try some long exposure landscape work in their off season and discover a few tricks to expand their sports portfolio. I remember being blown away by a slow motion photo of the Ferrari F1 team pit crew at work many years ago when every other shot on the day was probably taken at 1/1000 of a sec or faster (a dead still car with red and yellow movement streaks coming from the engine and wheels). Another F1 shot, a drivers' cockpit portrait, taken on an medium format camera for a Pentax ad.

Change your work flow.

Turn your usual flow on its head, breaking habits and repetition. Do a series of photos on a theme or specific subject or photograph to populate a story you have written (start a blog!), that is, make the photos the support for, rather than the main act. Make the photos different in style to your usual method, such as grainy black and white or muted, old fashioned colour (but try to avoid gimmicky looks that will fall out of fashion). Create or return to a project of connected images, its a good idea to have one or more of these up your sleeve as they can grow into a major work. An examples is the "Travellers" series. This really only started as "filler" or warm up shots taken while getting from one place to another. Many would not take in colour, so they became mono and film like to better suit their mood (1 of these is actually a film image...guess which). 

Look Harder/slower.

Slow down, observe and see new possibilities. After travelling I often find home a bit boring, but if I slow down and really look I start to see things on a different level or a different way. Some of the greatest works in photography's long history have come from a very limited geographical area or subject matter, for example the work of Gregory Crewdson, William Eggleston or Michael Wolf.  This often comes with the realisation that in a target rich environment I may have only been skimming the surface of possible compositions and viewpoints! This can also improve your photography, increasing you depth of perception and awareness of more worldly (non photographic) things and your understanding of your subject. Remember that some of the best known photos in history look deceptively simple and often are, but come from a deep understanding of the subject through patience and involvement. When asked, most of the great National Geographic or Magnum photographers will say that the most important part of what they do is along the lines of interaction and understanding, not gear or technique. One trick is to go somewhere without a camera and just look. I bet your shooting finger will itch pretty quickly or, as a less risky option, take just one small card to force good shot selection and a more watchful eye (or use a film camera).

Reduce your gear (just for now).

Look at your usual kit and pick out one camera and one lens. Go for a walk and see how many opportunities open up with this limited kit. This is probably how you started and may add some level of comfort and familiarity, lost to a larger range of kit. If you are a minimalist now, borrow or buy something you do not have, but nothing too serious, in fact something a bit silly is good like a "toy" or retro "legacy" lens adapted to your camera or even a novelty camera or an exotic and unfamiliar bit of kit. I have a clutch of old film cameras. Using one allows me several of the above tricks and is a good rest from more serious photography.

Print.

It sounds too easy, but printing previous work can get the creative hunger back. There is something about committing to print that changes the way you see your own work. Personally I find photographing to print far more productive than just shooting with the intent of only posting or storing. Sometimes just looking at your older images will bring something to life.

Read and look.

If you have a library of photo books, now might be the time to browse them. If you do not, the internet may provide or a good magazine (not photo specific necessarily) may help. Looking at the work of others may help you see the simple things that are all around us. My own library "is not going to move with us again" says my wife, as books are my weakness, but they never fail to inspire.

I hope this helps you when the creative river runs dry.