Writing your own spells can be much easier than looking at spells written by others. You can get creative and use materials you have close by and on hand.
That said there is a few considerations that may help.
When spell writing you may want your goals to be more reasonable. You will want a way to obtain them.
For example say you are looking to obtain extra income. A great way of writing this spell is to write it in the hopes of a raise if you work. A 50 to 1.00$ increase is reasonable for a raise. A raise higher than that is less likely to manifest and less reasonable.
Then you will physically want to do everything you can to meet your goal. You will want to do a proper job and get on well with coworkers.
Essentially spell work that is feasible should be a combination of magical practice or help with physical potential.
Casting an extra income spell when you don't work, don't have a source of income, and don't intend to, will not fair well.
It is more likely to fail.
In your job if you make 900$ a week and you intend for 2,000$ more your spell is not likely to come about and if it does it very well could be in a way you may not necessarily want. An inheritance.
Writing your spells can be powerful. I tend to write my own spells the majority of the time. I know exactly what I intend and being a little more specific helps to inspire me to fulfill my goal.
That said good luck. I am sure with practice you may really enjoy taking a more active approach in your spell work.
Ravenfeet has some great advice. Realistic expectations of any spell is one large and necessary step to the manifestation of your intention and craft. I believe most practitioners write their own spells or at least tweak a spell they have come across. You may also want to consider the many different types of rituals and spells while writing your own as you may want to draw ideas from previous rituals and energy workings that already exist. I know when creating my own spells I combine different aspects like charging items in moon light when the moon is in a certain phase then using that item in a spell or other aspect of the craft. Explanations can also help recreate a spell such as the specific actions and movements being detailed like clockwise and widdershins. I personally like to note why I am adding specific items to a ritual or spell so that I understand my own though process at the time. A few times it was stumbling onto a new herb that I then researched and discovered to be just what I needed to add to a new aspect of the craft I was currently working on. Recognizing my intuitions and synchronicities as valid parts of my craft early on helped to increase the desired results of my energy workings and the journaling did. First and foremost however your own spells and grimoire should be for you so I suggest organizing it to be easy for you to read but when going to publish including the details that could be forgotten that may be of help to others.
Many Blessings,
Katie
Below are some links you might find helpful when creating your own BOS or girmoire;
