I recently (Feb of 2016) pulled my homocysteine for many reasons including the following:
a) No doctor had ever pulled it for me as far as I know, even though there is a mountain of research behind its importance
b) Recent research shows it is a risk factor for erectile dysfunction since it lowers nitric oxide and accelerates plaque in the arteries, something I cover in my page on Homocysteine and Erectile Dysfunction.
My results, which was 11.3 umol/l, fall into what might be termed a "grey area" However, before I discuss my own results, let's look at Three Different Ways to Set Your Target Homeocysteine Level:
1. 12 umol/l to Avoid Erectile Dysfunction. A recent study look at non-diabetic patients with erectile dysfunciton and normal control subjects. This is a very important study in my opinion, because it matches what I often see on The Peak Testosterone Forum, i.e. men that appear to have no major chronic disease but can't figure out why they are experiencing erectile dysfunction. What this study shows is that these seemingly healthy guys have higher homocysteine levels on average: 10.7 versus 16.4 umol. In fact, if you look at the data for this study, you'll see that average lipid numbers were not that different for the two groups What really stood out most were varying homocysteine levels.
The researchers stated that "the reference range for Hsys concentrations has been proposed to be between 5 and 15 umol/L. Based on these data, we speculate that Hcys levels greater than 12.1 umol/L increase the risk of ED. Based on our results, the chance of developing ED is 80% in the cutoff point of patients with hyperhomocysteinemia." 
They also stated that men with elevated homocysteine had three times the risk of developing erectile dysfunction!
2. 12 umol/l to Avoid Heart Disease. Many commentators have noted that at about 12 umol/l, your risk of heart disease and cardiovascuclar issues go up. Here are a couple of examples:
"Plasma Hcy levels above 12-15 umol/l in the fasting state and above 40-50 umol/l after methionine loading is probably associated with increased risk of atherothrombotic disease." 
"The Tuft research team concluded that people with homocysteine levels greater than 11.4 mol/L have a significant risk of having a heart attack. These findings were published in the February 2, 1995 edition of the New England Journal of Medicine." 
NOTE: Elevated homocsysteine is associated with many other conditions as well, including "coronary artery disease (atherosclerosis), heart attack, stroke, peripheral arterial disease, venous thrombosis, deep vein thrombosis, pulmonary embolism, dementia."  If you find your homocysteine is above range, say 15 umol/l, discuss with your physician.
IS YOUR HDL LOW? My HDL has always been on the low side. I have read research that explains that some men just have low HDL and these men cannot improve their HDL via exercise like most men. One interesting explanation is that elevated homocysteine actually lowers HDL.  Now my homocysteine is not that high, but the commentary listed in reference #4 caught my eye, and I would guess that it is applicable to some of you reading this. Please see the reference for more information.
3. ~8 umol/l (William Faloon, President of Life Extension Foundation). William Falloon has an interesting discussion where he talks about how taking ibuprofen gave him early stage kidney disease and elevated homocysteine.  In the course of that article, he talks about aggressively targeting 8 umol/l:
"That meant my homocysteine reading should have been below 8 mol/L, whereas in fact it was a startlingly high 15.6. The only reason my homocysteine could be this high, I argued, was a failure of my kidneys to remove and neutralize the excess homocysteine." 
I was not able to find evidence that you have to be at levels this low, but it does seem prudent not to come anywhere near the 11.4-12.1 umol/l levels mentioned above.
MY PLAN OF ACTION: I would like to pull my homocysteine levels down about 10-20% to avoid coming anywhere near the above. To do this, I will probably consume more of the nutritional brewer's yeast that I consume, which is loaded with B vitamins. It's nasty stuff, but should help pull down my homocysteine levels. If it does not, then I may need to supplement B vitamins. (I do not recommend using synthetic folic acid, an unnatural form found in many of the cheaper multivitamins and formulations out there. It persists for a long time in the body.) I also will do a fasting homocysteine test, since methionine can raise homocysteine and I consume a fair amount of protein (for muscle building purposes). Many other things can elevate homocysteine levels from kidney disease to MTHFR, so do your research and discuss with knowledgeable physicians if this is an issue for you.
1) Metabolism, 2006 Dec;55(12):1564-8, "Hyperhomocysteinemia: a novel risk factor for erectile dysfunction"
2) Circulation, May 17, 2005 vol. 111 no. 19 e289-e293, "Homocysteine and MTHFR Mutations: Relation to Thrombosis and Coronary Artery Disease"
3) Indian J Chest Dis Allied Sci. 2008 Jan-Mar;50(1):39-48, "Homocysteine, Folic Acid and Coronary Artery Disease: Possible Impact on Prognosis and Therapy"
4) Circulation Research, 2006; 99: 565-566, "Homocysteine and Cardiovascular Disease Is HDL the Link?"
6) Life Extension Foundation, "When Homocysteine Levels Won't Come Down," by William Faloon