I wish someone would have told me back when I was first starting out about the differences between a beginner and an advanced witch. My path began many, many years ago when the internet was an infant. Except that then, trying to collect any credible information was still not to be trusted on the "World Wide Web" as it was then called. There were too many personal web pages created by amateurs in those days that it seemed like a dead end to even begin to do any research online.
I resorted to books and Yahoo Groups (remember this was 1998). It was tough, since there are so many different beginner's spell books, step by step instructions for rituals, elements, sigils, altar decor, candle color meanings, herb definitions, types of witchcraft, types of witches, history, yadda yadda yadda...and there was always something to learn! After I had squeezed every bit of knowledge and practice I could from each witch how-to literature, I was wanting more. Except, why was it that there were no advanced spell books or how-to books? It didn't take long for me to figure out that advanced witches needed no instruction. The didn't require pre-written spells listed in nearly every witchcraft book I owned. They created their very own custom spells based on their extensive knowledge of candles, oils, herbs, incense, ritual, spell work, and mostly...confidence and common sense. I was ballsy for the first year or two of my witchcraft studies...I performed as many different spells as I could. I made sure I performed at least one spell a day from the time I came home with my first set of witch supplies. I was in love with the entire concept, meaning, beliefs, and most of all I loved how practical it was. This is what I've been looking for my entire life, and there was nothing else like it. Creating your own spells from scratch requires a special technique to where you are capable, positive-minded, experienced enough to take from any situation, and customize a universal goal. My first suggestion is to first get to know your herbs and oils. I know my herbs and their uses by heart, I also own practically every herb or root used in witchcraft/hoodoo. Just start an herb collection by placing your dry herbs into a glass jar with lid (the type you would use for storing jelly in). You can also place them in bags & label with a magic marker. Make a habit to look up herbs which match your intention. For instance, if you were performing a reversal spell, then I would use the herb, "Agrimony". It is best used for return the favor...or a return to sender. Basically reverses a curse, putting it on the person who originally harmed you.
In a cleansing spell you could use Eucalyptus, Hyssop, Lavender, and/or Witch Hazel. When you are performing a protective spell, then you could try Red Sandalwood, Rosemary, Rue, etc. You can create spells with all types of herbs.
PRACTICE. A LOT. Keeping a grimoire, book of shadows, journal, or spiral notebook helps you to track how your spells were originally done. It will allow room for improvement giving you tool for perfecting your own spells. Keep trying different ways to make your spell tight as a drum so that it will thrive, bringing positive results for all involved! Always remember that you never stop learning as a witch. There is ALWAYS something else out there that you didn't know could be useful in performing successful spell rituals! Finding knowledge may not be as hard as it was back in my day, but finding the right literature and research can make a huge difference. Especially when it comes to trial and error as with spell work practice. It is important that you fail a few times before getting your spell to work. Once you are able to witness the outcome of a spell...there is nothing else like it! Makes it all worth it in the end no matter how hard we worked, how long we meditated, or how many pages we have read. Don't give up!