@noraasnave, try this to spice up your photographs a bit – nothing wrong with the ones you have taken so far – they bring back fond memories of my ARMY service.
Change the camera’s point of view: squat down; climb to a higher point (safety first Marine! ;) and also get closer, way closer! This can dramatically improve portraits. You can always take the photo most take where you see someone head-to-boots; follow up with one where you capture the image of the person/group from the collar up – it removes the environment to stress the individual and /or relationship – Brothers in Arms for ever. Again, consider shooting from different angles (stand low/hi and to the side to make the subject/s vanish into the horizon).
With the advent of digital cameras you have now the possibility of making a photo both in color and also B&W. B&W images stress the subject matter. A rifle resting on a wall, a helmet on a table, boots by the door, all part of the Marine’s gear become now ageless icons instead of a products from a surplus catalog, if you know what I mean.
B&W also works really good to for those people showing their age. The old lifetime Marine, the man at the local bazaar that appears to have wondered the earth for a thousand years, etc. Look for contrast of surfaces too (an unshaven face, dirty hands (e.g. say, a mechanic’s), etc.
For landscape I would continue with color; use the dusk/dawn light. It works better more often than the noon sun.
Sharing others’ sentiment, thank for serving. Now get home safe.
Semper Fi.