As Sabotloader said it can and will get a Crusty top over it once it has been exposed to air. I usually make sure the cap it tight after use and store it lid side down to minimize that some. Just try to carefully get as much of that out before you start so you don't have small bits in the oil, as it will wind up in the finish. It is very easy to use and to touch up with. Just buff out a spot and apply a bit with you finger till you get it blended in. I usually hand rub it in with my fingers so there is no brush marks, but it does self level to some extent. Apply with light coats and buff lightly between with 0000 steel wool. I have done several stocks with Tru Oil and made them look like new. I just re-finished my Ithaca 37 Deer Slayer with it and it looks great. As with anything just take your time and you can get a very nice finish that will last a long time.
Good luck,
ShawnT