1 pointSure, you can add another booster packet or some LME, liquid malts extract. MB sells those in Pale, Smooth, and Golden. You can read the descriptions on the online store. Two booster packs will raise the ABV about 1%, without changing the taste of the beer. I think one pack of MB LME is about .55 lbs and also adds about 1% ABV but can change the flavor of the beer. Look thru the recipes and you'll see a lot of them will show either using a bag or two of booster, or a pack of LME, to provide a little kick from what the standard can or craft refill would have. Those standard small cans of HME, are pretty weak in ABV by themselves and need some booster or LME to kick them into gear IMO.
1 pointAnything that contains fermentable sugars will raise it. Table sugar, malt extract, honey, Lucky Charms cereal, agave nectar, maple syrup...etc., etc. Each of those will have different impacts on the final taste of the beer, though. I recommend doing a web search, as there are too many variables to list. Additionally, you can just add booze to the LBK or to each individual bottle at bottling.
1 pointWhat I do... http://www.homebrewfinds.com/2011/09/tip-using-star-san-in-spray-bottle.html 6 cc StarSan INTO 1 Gallon Distilled Water (128 OZ) 3 cc StarSan INTO 2 Quarts Distilled Water (64 0Z) 1.5 cc StarSan INTO 1 Quart Distilled Water (32 0Z)