After your GCSEs, it will become increasingly apparent that your school will no longer provide you with stationery, assuming that it did in the past. With this in mind it is important for you to select your own. Now your stationery is not entirely responsible for your academic success, but it having good stationery puts you in a position to do well, provided that you take other steps as well.
That said, how do you decide what you need? Well that's a tricky question as everyone has different needs when it comes to picking out stationery requirements. Some people go for the minimalist approach and come to sixth form, college or university with almost no stationery at all, whilst others come with a stockpile of stationery which covers every eventuality. The approach given below is a compromise between the two and should give you some ideas on how to get started.
By this point in your school career you should know what kinds of writing instruments you need, but for clarification you need at the very least a pen, pencil, rubber, and sharpener. Remember to carry spare pens, pencils and rubbers as it is not always convenient to buy them when you run out. Depending on your subject you may also need a ruler. One big and one small one should suffice.
Additionally, consider buying soft grip pens and pencils since you will be doing a lot more writing at sixth form and university and may develop callouses with ordinary pens and pencils. Also, if you're one of those people who like presenting their work nicely then consider highlighters and gel pens, but this is not necessary.
Care should be taken when using fountain pens as they can blot and ruin a page of work. Also, ballpoint pens may be more comfortable to use, but cartridges do rupture and this can interfere with the action of the pen. Correction fluid is inadvisable as it is messy and often forbidden in examinations.
Now that you have writing instruments, it is worth considering what kind of paper you want to write on. If your written work is not up for inspection then cheap pads of lined A4 paper or scrap paper from an A4 printer may be enough. If your written work is to be inspected then consider buying quality A4 paper (or A3 paper if you are drawing). You can normally tell what quality the paper is simply by rubbing it with your fingers. Poor quality A4 paper can often feel like newspaper or almost like tissue paper. Also, higher quality paper will be thicker and thus the paper density (GSM) will be higher. The GSM of high quality paper is usually between 80 and 100 GSM.
The easiest way to store paper for day-to-day use is by using an expanding organiser, which comes with many slots for storing paper. If you want a long term storage solution for paper then consider ring binders and lever arch files. The latter is used when storing excessive amounts of paper in an organised manner. That said to use ring binders and lever arch files, you may need a hole punch should your paper not come with pre-punched holes. This is usually the case, but not always. Should you want to avoid the hole punch then consider using box files for large amounts of paper. Just bear in mind that should you drop them whilst open then the paper will scatter everywhere.
As for your writing instruments, you should really use a pencil case to store them. You can get a single or multiple tier pencil case depending on your preferences, but it is recommended that you use a multiple tier pencil case. This is because these often have slots for holding all your writing instruments which prevents them from moving during transit, whereas a single tier pencil case often has lots of space for quashing stationery together. Also, consider having a back up pencil case should you accidentally lose your main one.
Now you need a bag to store your books, files, folders and pencil cases. The most common ways to do this are to use a satchel or a rucksack. Occasionally people do use holdalls, but generally these are quite impractical for day-to-day use. As always, make sure you have a spare in case your bag goes missing or gets damaged. The latter can occur when you overload your bag with heavy objects, which causes the bag to split.
These are all tools which can help you keep your life organised whilst at sixth form, college or university. They include plastic wallets, sticky tabs, button wallets, post-it notes, cellotape and scissors. These can all be useful in one way or another, but it is recommended that you consider how you will use them before you buy them. Having an abundance of stationery is great when you need it, but not so much when you don't.
One thing which you should consider buying is staples and a stapler. This is because oftentimes you will have a lot of paper which needs organising into sections and provided these sections are not too big, a stapler is a convenient way to keep things organised. Paper clips and folders also work, but are less effective at doing the same task.
Invest in a good laptop and a scientific calculator. You will find many uses for these at sixth form and especially at university. Your course may not explicitly require a scientific calculator, but it's always a good thing to have one in case a situation arises where it is needed. Some people also invest money in iPads, smartphones and other kinds of gadgets to keep themselves organised, but this is purely down to preference.
Whatever stationery set up you decide to have, just remember that it is for your benefit and no one else's. Many people have different preferences when it comes to what stationery they decide to have, but so long as you make good use of it that's what matters most. It is all fair and well buying a pack of 20 highlighters, but if you never use them then they're of no use to you.