In nature, everything that was once alive naturally will compost eventually. However in an urban home it is often impractical, or difficult to compost all our kitchen scraps and organic material.
In theory you could add cotton clothes and all paper and card, as well as meat, fish and all fruit and vegetable waste to the compost heap. In practice many of these things will take an age to break down if your heap is not hot enough, and might well attract pests. You might also find your pets take too much of an interest in a compost pile that includes all food waste.
There is also a concern about whether composting materials that are not entirely organic might lead to chemical pollutants in the finished compost. For this reason many people do not add printed paper to their heaps, to prevent ink particles ending up in the finished mix.
Just how strict you are with regards to such things will depend on how environmentally friendly you are hoping to be, how accessible your compost is and the range of organic material you have available to you.
The ideal compost pile needs a good balance of dry material (small clippings and cardboard for example) and wet material (vegetable peel and lawn trimmings).
For most of us it is best to avoid adding meat or cooked matter to the compost heap. All other food waste such as tea bags, coffee grounds, spoiled vegetables and peelings are more than adequate. But of course if your heap is very secure, and pests are not an issue in your locale meat and even cooked foods might be suitable too. These are more likely to bring potentially harmful pathogens to the compost mix, so it is important only to include them if the compost heap is very hot and fast acting.
If you find yourself with an awful lot of one thing it is best to try to mix it through the compost pile. Certain items such as citrus fruits can slow the compost down if added in too high concentration due to their acidity. But of course the occasional left over orange or a few citrus peels are not going to be problematic.
If you are trying to tidy up your collection of kitchen scraps heading for the compost heap I suggest you invest in a compost pail – they make being Eco friendly much more tidy! Having a compost crock also encourages the whole family to recycle as much organic waste. After all if it is sat on the counter top there is no excuse.