If you have to ask someone to give you a spell, you don't need to be casting one. I'm not saying that I'm against "swapping" spells (like if you're a solitary Witch but you sometimes get together with other Witches and share things, whatever), or even asking for help (everyone hits mental blocks sometimes), but if you have to ask someone to give you a spell because you can't come up with anything on your own, you aren't ready for it. I've asked for spells before. Mostly it was to try to find a beloved necklace of mine. I had written several and none of them ended up working. I asked for help with that, got some ideas for other means to find it, and eventually gave up on it (I started to think my ex threw my necklace away, and I still do).
Spells are not "cool" or a trend right now, they're serious. For one to work, you have to be invested in it. You have to put your energy and emotions into creating it and casting it or it's not going to work. You can't just open up a book or look one up online and say the words and go through the motions and expect to instantly get what you want. You have to want it bad enough to WORK for it. Do you think that everyone makes it as an actress just because they want it? No, unless they have always known the right people (ex. their parent(s) were in the industry), more than likely they had to bust their asses to make it big. Magick and spells do not replace hard work and commitment, but they can help the process, smooth it out a little, help you find the right path for success, etc.
Lets look at an example. Say you REALLY need/want a job. You do a spell to help you find one, and then you just sit on your butt everyday expecting someone to knock on your door and hand you a job. It's not going to happen. But, doing a spell to help you find a job may increase your chances of finding a job that you at least like, if you go out there and really try to find one.
I get e-mails from people all the time asking me for spells and tell them all the same thing. Absolutely nothing (well, usually, sometimes I respond to tell them "no"). I'm not going to give out spells, but if you're genuinely interested in this path, I will talk with you and try to give you suggestions for where to start. I've given out meditations before (mostly taken from books and then modified by me to suit my needs), I've talked to people, I've tried to steer people in a direction that will be helpful for them, but I'm not going to hold your hand and walk you through every single step of everything because it's something very personal. I can help, but I can't lead you along your path because what's right for me may not be right for you.
And just for the record, those spells for my necklace are the only ones that never worked, so after a 4th attempt, I gave up for good and decided that it wasn't meant for it to return to me.
Spells work by manipulating energy, basically. There's energy everywhere, in everything. When you learn to raise energy and use it for your purpose, you'll be able to cast a spell. Or at least that's how it is for me. I've always been sensitive to the energies around me, and I've always been comfortable working with it, even before I knew what it was.
Emotions are one of the best resources for spells. You need an emotional connection to what you're doing, and your emotions can be a very powerful source of energy for casting a spell. That's one reason why you need to watch how you feel when casting a spell. If you're full of negative energy, your spell may turn out negatively. It's ok to do a spell because something makes you angry and you want to change it (for example, if war makes you angry, it's ok to do a spell for the safe return of soldiers or for peace to come to the warring area, etc.). But, you need to to use your anger in a POSITIVE way. You also need to believe that your spell will work. If you keep thinking that it's not going to work, it's not going to work. The power of positive thinking and all that, as well as the law of attraction, comes into play with spells.
Another important aspect of casting a spell that some people seem to overlook is keeping your mouth shut about any spells you cast. When you cast a spell, keep your mouth shut! Don't tell people about it. The emotions of others can interfere with your spell once they know about it. Say you tell your best friend that you just cast a spell and s/he thinks you're nuts for it, even if s/he doesn't say so. That negative outlook can mess with your spell.
Don't expect your spell to manifest overnight. Spells will very rarely manifest that quickly. It can happen, depending on the spell, but it's unlikely. Don't give up on it and start thinking it didn't work just because you didn't wake up the next morning to results. Give it time, and be patient.