Lavender Oil. Get a good quality, "pure" lavender oil and put it on areas you have just bumped to prevent the bruising. It also prevent burns from blistering, but make certain you get a pure essential oil.
If you didn't catch the bruise on time to prevent it, the oil will also help to heal it and lighten it more rapidly. I found out just how good it was for burns after draining boiling water from cooking fresh peas into a strainer that was supposed to have dropped down as the veggies were poured in. I had it upside down and the boiling water completely covered my hand. I immediately grabbed the lavender oil and lavishly poured it across my hand, full strength. The burning let up quickly but started back up within less then a minute so I rubbed more on and kept this up for an hour. Every time the burning started back up, I put more oil on. After an hour I was only putting it on about every 20 minutes. After two hours about every 40 minutes and after 3 hours I only used it once an hour, but it was no longer burning. I continued to rub it on until bedtime, and when I got up in the morning there was no blistering and no pain. I still put it on 3-4 times the next day just to make certain but it was gone. For cuts or sores that may get infected Young Living has an essential oil called "Thieves." It is a miracle worker.
I was out walking and coming down the hill toward my home, I wasn't watching and my foot went in a pot hole and I went down, cutting a rather large hunk of meat from the side of my thumb completely away from the side of the thumb nail at the top to almost the bottom of the nail. I came in and washed my hands immediately and wrapped it snuggly with a bandage to hold the large meaty section together so blood could reach the separated part. It was the July 4th weekend and I was not going to any "After Hours" or emergency rooms, so I poured Peroxide over the cut before I bandaged it, and after I put the bandage on I left an opening at the top where I could pour drops of Thieves into the section split away. Three days later, with the holiday over I went to After Hours to have a doctor look at it, as that large hunk of meat was turning white. He looked at the cut and asked me what I was using on it that stained my thumb the orange/brown discoloration. I told him "Theives," but he thought I said leaves, and double checked again, so I spelled it out and told him it was an essential oil. He said he had heard about essential oils but never really looked into them.
He told me that falling on pavement like that is the dirtiest place to fall and get injured, yet this cut had absolutely NO infection in the wound. He told me to keep up doing what I was doing and checked to make certain I was up to date on my Tetanus and sent me on my way. He told me I may possibly lose that large hunk coming down the side of my thumb, but I should be able to just clip it off if it starts to die. There was a blood blister under the raw wound that was keeping the two sections from pulling together. I wrapped the bandage a little tighter to pull them more together and kept putting Thieves on the wound for about 10-12 days. When I went to change it one morning the two pieces were pulled together and the blood blister gone and still no infection. I let air get to it to heal more but kept using Thieves 3-4 times a day or after having my hands in water. Another week and it was all healed and I didn't lose one bit of that thumb in the process.