was wondering if there was a way of figuring out correct arrow length via tuning or if you just cut the arrow to a length you are comfortable with and just play with tip wieghts to tune,  Im very new to this and dont no anyone that shoots trad.  I come here for advice and everyone on this site has been so great appreciate all the past adn future help thanks everyone  

The nice thing about arrows is that there really is no 'too long'. When in doubt I start with a full length shaft and tune from there.

You can always cut them shorter.

It depends on what type of arrow,are you asking about,carbon,wood or aluminum.If it is carbon I never just cut them down until I have shot them at full length.Wood and aluminum you have so many different spines to pick from.Carbons don't come in as many different spines,so you pick a starting static spine and you adjust the dynamic spine by shooting and trimming and or adding weight upfront until you get the correct spine for you and your bow.There has been alot of used carbons for sale that were just cut to a certain length and guys were not satisfied with the arrow flight no matter what they did to them.JMO