Lots of people have listened and watched others in Main battle it out with blood magics and the way they shouldn't be used in main. In this discussion, I'll be adding my own views and the way I think Blood magic should be used, not the way others do it. I'm in no way trying to offend any one who might control blood magics: Rom, myself, and any other vampire and or human or other species. 

Common Uses:

• Curing Sickness
• Healing
• Locking Joints in battle so the enemy can't move
• Fending off Poison
• Controlling someone's life force and essence
• Creating Children 
• Causing someone's body parts to explode

These are just a few but I want to put some emphasis on a few that I think should have lower effects. Some I haven't seen since the middle of the Void war, like the exploding body parts one. Now... :

• Curing Sicknesses: Most people come in with either food poisoning or some other type of sickness that isn't fatal, such as a sinus cold or the flu. In cases like this, I think that Blood magics could be used to help them get comfortable, but that's it. This would cure only a small part of the sickness so that they can breath *ok* with the sickness but have to keep it. Makes it more realistic anyways.
• Healing: I can't say much about healing. This is one of Augustus's personal abilities and he doesn't use it all that much. Rom does a pretty good job when healing with his and it should be kept the way it is.
• Locking Joints in Battle: This hasn't been used much lately, though Augustus used it on either Rom or Mack's arm to lock it so that he could block an attack. I don't see a problem with this one because it was used in defense. Other uses have been to get instant damage on the opponent but that's been long unused. It wasn't a godmoding move because if you're a blood mage or can use blood magic, its one of the powers you can use. However, be careful how you use it because it can get you on the bad side of others oocly.
• Fending off poison: There are many ways that others do this and Blood magics are one such way. This ability causes the victim or patient to bleed out the poison, whether in the form of sweat or through a cut in which they got the poison. I feel that in this case, the user should have to absorb some of the poison to fully absolve the patient of its ailments. This would partially weaken them to further attack physically though not mentally. 
• Manipulating the life force/essence of another being: This is something that both Rom and Augustus can use. Most of the time it's used to heal, though its a double edged sword. When used in combat, it could be used to slow down another or possibly to drain that person of the life essence in an all powerful move of magic. I'd advise against it, but its still an option.
• Creating Children: This is one of the things Rom told Augustus not to do when he gave Augustus his powers. However, Augustus found a way to use his own blood to do it, the blood of a vampire in an old spell of the clan that Sired the Giovanni. The children if created in Rom's way would be evil, benevolent and possibly would try to mass murder thousands of people. The first being the mother/father and sire. 
• Causing Someone's body parts to explode: As the lock jointed one, this hasn't been used but is a valuable weapon when surrounded by enemies. If one was to use this, he'd use it in the battle field in the middle of a war or even in another type of environment. This only causes other players to bitch, so to speak, in pm's with the user and could lead to controversy with the DMs of the site. Romulus showed us a great example of this in the void wars when he blew himself up to rescue the heroes and therefore destroyed an army of creatures.

There's a lot more powers and abilities that could be involved with Blood magics, but these are the ones we either see daily, or we've seen in the past. I'm not saying I'm an expert on Blood Magics, but I thought that I should make a try at it. If there's any thing you could add to make this better, then please do so in comments. I'd like to thank Rom for giving me permission to do this blog. If any of it isn't to your liking, let me know and I'll take it out or change it so that it sounds better or works better with you.