Spells, and rituals are like wonderful recipes that allow you to cast your intent into the universe in order to manifest your desire. When using spells and rituals that you did not create you may find that you do not have all the ingredients that are needed, and will have to go about substituting, and reworking the spell, or ritual in order for you to be able to cast it. In order to do this you are going to need to understand the fundamentals of how magick works along with the metaphysical properties that you are trying to use in order to act out your desire. There are many things that may need to be substituted, if you are unable to acquire them for spells, and rituals these would be such things as certain candles, herbs, or crystals, along with many other things. When substituting you are primarily trying to match the metaphysical properties of the construct that you are trying to substitute. This is so that you can still continue to get the specific energy that you need for your intention, so everything will manifest the way it is intended. All the metaphysical properties of the item should be taken into consideration to make sure that they fit into the spell nicely, and do not contradict any other parts of the spell, or ritual, or your intention.
If the spell, or ritual calls for a specific color of candle, and you do not have it it is a good idea to either use white, or black candles in place of them. The reason that these colors replace all the other colors is because they have energies that represent all of the colors, and because of this have some of the energetic properties of those colors which can be harnessed, and used in your magickal practice as a substitute for the others. If you are not allowed to have candles for any reason you can always use electric candles, and these will work just as well for your practice. Candles are primarily used in magickal practice as an energy source in order to generate a specific energy based primarily upon the color of the candle. Electric candles will still be able to generate spiritual energy from there electricity when they are on. If you don’t have candles, and you don’t have electric candles you could also use crystals because crystals give off energy, and specific types of energy depending upon what type of crystal it is, or you could also use sigils that have the intention to give off energy, or a specific type of energy.
If a spell, or ritual calls for a specific type of crystal you will be able to find a substitute for it by simply looking up the metaphysical properties of that crystal, then you will be able to replace it with any crystal that has close to the same metaphysical properties. Crystals that are the same colors usually share some metaphysical correspondences in common, and will usually also work similar to each other. Crystals are also used primarily as energy sources, and will be able to be replaced by a candle, sigil, or herb of the same energy. Clear quartz, and selenite are two very good stones that will bring more spiritual energy into your working, because of this the stones are very useful, and are pretty good to have in almost every spell and ritual.
If the spell, or ritual calls for a specific type of herb you will be able to most of the time swap it out for something that has the same metaphysical properties. It is important to keep in mind though that what you are doing with the herbs should be taken into consideration before you, come in contact with them, burn them, or digest them, and should always be looked up to make sure that they are safe to handle. This is also true of oil, teas, food, waters, and many other substances that you will be substituting in spells, and rituals. Herbs that you only need the energy of can also be substituted by sigils, crystals, or candles of the same energy.
There are no crystals that can substitute all other crystals, and there are no herbs that can substitute all other herbs. There are some ingredients that do very well in a lot of different metaphysical places, but are not substitutes for all. These ingredients do cover very wide ranges, but in certain areas will fall short, not be specific enough, or will actually do the opposite of what you want. It is important to take time and look for a substitute that shares the most similar energy to what you are substituting, so all the energies can stay very in common with the original spell, or ritual allowing it to still manifest the same way. Items that are substituted out will not be completely perfect to the energy of what they are being substituted for, but need to be close enough in order to give off similar energy. They will never be completely the same because no two items share exactly the same energies.
You may also want to rework some things so that they fit better in your practice such as the words, language, references to deity, or many other things. The words of the spell, or ritual can pretty much be switched around for anything as long as your intention is shown, and stays the same. The language is also able to be changed into whatever language that you would like. Certain languages may allow you to voice your intention more prominently, and may have metaphysical properties that you want to empower your working with. Any reference to deity can also be switched out for any other deity, or deities that would fit good into the spell, or ritual. In ceremonial rituals this may be seen as disrespectful to switch out wording, language, or deity, and the traditional form should probably be stuck too as a sign of respect for ceremony, and tradition. You may also want to rework some of the steps of the ritual, or spell in order to make it more accessible to you. To do this you should know why that step was included, or not included in the first place by looking at its role it plays in order to decide if the ritual, or spell needs it, or not. you may also choose to do something that is similar but a little bit different such as drawing different symbols or finding another way to destroy something instead of burning it. It comes down to finding things that will still allow the energy to manifest in the same way, while staying true to the energies of the original ritual, or spell.
Once you understand more about the craft, and how magick works you will be able to do this so much easier, because you will have the knowledge that allows you to interact with certain fundamental parts of the spell, or ritual, and be able to change them in order to make them how you would like. By keeping all of these things I have mentioned in mind you will be able to switch out ingredients, and be able to rework spells, and rituals to help them fit your needs as a practitioner. Magick is a lot like cooking and once you understand the recipe you are able to change it, and make it better suit your taste.