Get to the real issue; deal with the task at hand: “After avoiding the thorny question of tax reform for months, Congress finally got down to brass tacks last week and drafted a preliminary proposal.”
Also, get down to bedrock or the nitty gritty or cases. Deal with the essentials; come to the point. For example, Stop delaying and get down to brass tacks, or We really need to get down to bedrock, or He has a way of getting down to the nitty gritty, or Let’s get down to cases. The origin of the first phrase, dating from the late 1800s, is disputed. Some believe it alludes to the brass tacks used under fine upholstery, others that it is Cockney rhyming slang for “hard facts,” and still others that it alludes to tacks hammered into a sales counter to indicate precise measuring points. The noun bedrock has signified the hard rock underlying alluvial mineral deposits since about 1850 and has been used figuratively to denote “bottom” since the 1860s. The noun nitty-gritty dates from the mid-1900s and alludes to the detailed (“nitty”) and possibly unpleasant (“gritty”) issue in question. The noun cases apparently alludes to the game of faro, in which the “case card” is the last of a rank of cards remaining in play; this usage dates from about 1900. Also see to the point.