To really start with the basics your handwriting has a baseline which can be the line of the paper you are writing upon or lacking that seen by drawing a line from the bottom of the first letter to the last ignoring if it goes through any of the letters written. This we refer to as a baseline or line of reality. You will find many variations in just this one thing. If the writing clings to this line even between letters the writer is exercising supreme control or on rare occasions actually uses a ruler to direct their writing. This used to be done by people with really bad eye sight especially when learning to write. A young persons writing may look like it was written by a drunk rising off the line and then falling below. Their emotions are all over the place and often their hand and arm control are lacking. A mature baseline normally keeps close to the line with small variations because of the letter forms. However, a baseline that angles downward indicates a problem. It may be temporary depression, tiredness or just pessimism. On the other hand one that angles upward is enthusiastic, spontaneous and upbeat.