I haven't made any posts from these because they aren't anything I have the knowledge or skill to detail in any way. Some of these are photographic, image manipulation, and printmaking techniques that are going to require a little more information, equipment, or space than the average project makes use of. There is a wealth of information all over the web for these ideas.
I leave you to explore them at your leisure.
Pinhole: Use a lightproof box with a small pinhole as a lens to capture images on light-sensitive material without a traditional lens/camera.
Sabattier Effect: Create a halo-like effect around objects by exposing a photo to light during development.
Light painting: Use a handheld light source to create a design or pattern in a long-exposure photograph.
Lensbaby: Use a special lens that creates effects by intentionally introducing optical aberrations.
Lens swapping: Swap lenses during a long exposure to create a multiple-exposure effect.
Bokeh: A blurred, out-of-focus background with shapes and colours.
Panning: Follow a moving subject with your camera, creating a blurred background and a sharp subject.
Reflections: Use reflective surfaces like water, glass, or mirrors to create abstract compositions.
Shutter drag: Slow your shutter speed to create a sense of motion and blur.
Freelensing: Detach the lens from the camera and hold it in front of the sensor to create a soft focus effect.
Intentional camera shake: Deliberately move the camera while taking a photo to create a blurred image.
Toy camera photography: Use a toy camera or a camera with a plastic lens to create a lo-fi, distorted, and dreamy effect.
Slow sync flash: Use a slow shutter speed and a flash to create a sense of motion and blur.
Forced perspective: Use optical illusions to create a distorted sense of scale or perspective.
Macro photography: Get up close and personal with small objects, like insects, flowers, patterns, ephemera, etc. These are just close-up shots.
Long exposure: Take photos with a long shutter speed, creating blurred images of moving objects.
Light trails: Take photos of moving lights.
Shadow photography: Capture interesting shadows, often using natural light.
Multiple exposure: Take multiple photos on the same frame, creating a combination of the two (or more) images. You can do this with a film camera, or by using software to do it with digital images.
Solarisation: Partially reverse tones in an image.
Zoom burst: Use the camera's zoom function while taking a photo to create a radial blur effect.
Focus stacking: Combine multiple images taken at different focal points to achieve greater depth of field and sharper focus.
Intentional camera movement: ICM involves purposeful and controlled movement of the camera during exposure.
Brenizer effect: Refers to creating a wide-angle photo with a shallow depth of field by stitching together multiple images taken with a longer focal length.
Liquid emulsion: Liquid photographic emulsion is applied to surfaces other than photographic paper, allowing them to be developed like photographs.
Chemical etching: Transferring a photograph onto a metal plate coated with a light-sensitive emulsion, followed by etching to create a printable image.
Solar plate etching: A technique that uses sunlight to expose a printing plate.
Gumoil printing: Coat paper with a light-sensitive gum bichromate mixture, then apply an oil pigment to create a unique handcrafted print.
Embossing and debossing: Create raised or recessed surfaces in prints by using a variety of methods, such as a press or hand-tooling.
Chine-collé: Collage thin papers onto a heavier support paper then print the collage.
Collagraphy: Create a collage on a plate or board using materials such as paper, fabric, string, and found objects, then ink and print it.
Encaustic monotype: Paint with molten wax on a heated surface, then transfer the wax to paper.
Hand-drawn litho plates: Use a stone or metal plate to create prints by drawing directly on the plate with a greasy crayon or ink.
Photopolymer gravure: Similar to solar plate etching, but uses a photopolymer plate that is exposed to a digital negative.
Smoke Printing: Use smoke from a controlled flame to create on paper or other surfaces.
Chemical Resist: Use chemicals or substances to create a resist, preventing ink from adhering to certain areas of the printing surface.
Tilt-shift: Causes the illusion of the middle third of an image being a model or something small.
Gels: Use pieces of plastic, glass, or other transparent material over the lens or flash to alter the colour of the image. You can also spread transparent colours, soap, oils, etc. on them before you cover the lens with them, to further impact how the image is altered.
Manipulations and filters: Use preset digital filters or program your own. Can be used to augment colours, shapes, textures, clarity, etc.. Can be used in conjunction with other techniques.