Well first off is that your power and success rates will grow as you do more and more magic and your mind develops, it is important to do power meditation to help boost this.
Also alot of people believe that it is important that you perform the ritual on a certain time of day, moon cycle and even day of the year, for example tomorrow it is the autumn equinox and at this time it is good to start new things so a ritual for say a new love or job or whatever would be stronger done on that day.
Another important thing to do is that after you have done your spell/ritual just forget that you have done it dont even think about it, if you do your mind wont be able to concentrate on making it happen instead you will look for signs of it that dont exist, it is important to let it go from your mind and let your subconscious deal with it.
Although at the end of the day some magician find spells easy to cast at any time any place and with no planning or anything, this is true magick in my opinion, being able to effect the physical world at any moment with just your mind, but this doesnt work for everyone and lets face it magick is alot more fun and can be alot stronger with a full ritual and groups can make spells stronger to.
I hope this helps, sorry if i went off on one, if you need any more help feel free to ask or contact me directly.
"To the brave belong everything!!"
HAIL SATAN!!