It is so much easier to lay shingles when there are lines.
How to make sure your shingles are straight. Keep your sixth course tabs intact. Go buy a few bundles of 18 inch no. Follow the guideline you created to keep the shingles straight. For your fifth course cut off half of the final tab.
Insurance companies will try to not cover replacing your roof so having a professional there will help keep them straight. Make sure he or she is accompanied by a professional contractor. A half tab off for your first course shingles a full tab for your second course shingles. You can also purchase these as sidewall products in a variety of styles with mill run faces or grooved or sanded faces.
As you continue follow the pattern of lining a full shingle up against the next and nailing it into place. Depending on the type of shingle the lines are different when using 3 tab shingles or if you are using dimensional shingles. Continue to roll out more starter and align the lower edge with the roof edge. So your next course of shingles should cover the nails by 1 inch vertically.
Roll out 3 feet of the roof starter roll at one corner of the lower edge of the roof. Alright now that you know what to do on to the list. These come in rebutted and resquared with a regular straight butt or with a variety of other butt shapes such as round and etc. The hip was 30 x15 the center line helped keep the rows from snaking.
Run a course of shingles followed by another course until the shingles create a straight peak across the roofline of the house. Cut your last shingle on each row to size repeating all the way to the ridge. Usually the following cuts are useful. 1 grade red cedar shingles for the dormers.
This method worked out well for me when roofing the hip portion of my home. On the front back of the home horizontal.