Someone asked this on a flying blog and while, I was taught to anticipate turns and my Garmin 430 will anticipate turns I don’t remember any specific guidance on the matter, so I looked it up. I found this in the AIM.
5−3−5. Airway or Route Course Changes
a. Pilots of aircraft are required to adhere to airways or routes being flown. Special attention must be given to this requirement during course changes. Each course change consists of variables that make the technique applicable in each case a matter only the pilot can resolve. Some variables which must be considered are turn radius, wind effect, airspeed, degree of turn, and cockpit instrumentation. An early turn, as illustrated below, is one method of adhering to airways or routes. The use of any available cockpit instrumentation, such as Distance Measuring Equipment, may be used by the pilot to lead the turn when making course changes. This is consistent with the intent of 14 CFR Section 91.181, which requires pilots to operate along the centerline of an airway and along the direct course between navigational aids or fixes.
b. Turns which begin at or after fix passage may exceed airway or route boundaries. FIG 5−3−1 contains an example flight track depicting this, together with an example of an early turn.
c. Without such actions as leading a turn, aircraft operating in excess of 290 knots true air speed (TAS) can exceed the normal airway or route boundaries… Consequently, the FAA expects pilots to lead turns and take other actions they consider necessary during course changes to adhere as closely as possible to the airways or route being flown.