mean that a district court may excise individual portions of the Guidelines along the way as it performs an otherwise by-the-book Guidelines analysis, end up with a sentence with built-in variances, and never even know what sentence a true, rigid Guidelines application would yield. In practice, however, appellate courts expect district courts to first obtain the true Guidelines' sentence range and circumscribe their United States v. Booker-granted authority to post-Guidelines analysis "variances.” Irizarry v. United States, 553 U.S. 708, 710-16, 128 S.Ct. 2198, 171 L.Ed.2d 28 (2008). A district court that attempts to vary from U.S.S.G. § lBl.l’s basic sequence most likely acts procedurally unreasonably. See Gall v. United States, 552 U.S. 38, 51, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007) (<HOLDING>). United States v. Nolf, No. CR 10-1919-002 JB,
holding that despite the advisory nature of the sentencing guidelines they remain the starting point and the initial benchmark of a district courts sentencing analysis the district court should begin all sentencing proceedings by correctly calculating the applicable guidelines range and keep that range in mind throughout the sentencing process and that failing to calculate or improperly calculating the guidelines range  or failing to adequately explain the chosen sentenceemdashincluding an explanation for any deviation from the guidelines range constitutes significant procedural error  holding that a district courts treatment of the guidelines as mandatory renders a sentence procedurally unreasonable holding that although the guidelines should be the starting point and the initial benchmark of calculating a proper sentence the district court should then consider all of the  3553a factors to determine whether they support the sentence requested by a party holding that the district court committed procedural error by failing to provide an indication of what facts it relied on to make a significant variance from the advisory guidelines range holding that a sentence is procedurally reasonable if the district court committed no significant procedural error such as failing to calculate or improperly calculating the guidelines range treating the guidelines as mandatory failing to consider the  3553a factors selecting a sentence based on clearly erroneous facts or failing to adequately explain the chosen sentence emphasis added