I think we dont usually have the habit of bringing the GK out. Even when its a clear cut that the striker going to score we just prefer to let the GK handle it by default. But bringing out the GK has it advantages as well. Especially during certain events which is:
1. Long Ball Play
This is a very tricky position as well. To rush out or not to rush out. A nice tip i want to share is you just bring out the GK if the ball has been played in the center of the field. If the long ball is being played of the wing then better just guard your post since it is not a direct treat to your goal.
When you bring out always estimate the speed of the ball. If its too fast for you to rush out then stay in your box. If its high in the air go out and get the ball. For me i just bring out the GK until near the end of the box and estimate the speed of the ball. Its a save distance for me to actually plan my move base on the situation.
2. 1 on 1 situation
If long ball is your problem then this should be your no.1 problem in your list! This is the most confusing and tricky part in the game. Its either you stay back or you let them score. You go out and they might shoot the ball into the net. So which is the most safest route?
Another tip is you must test your opponent composure as well. Same like you, they feel nervous to score. Since its only you and him at the back end, his confidence to score is higher than your chances to save. So you must do something which he cant predict.
One of the move is to measure the distance between him and you GK. Bring out your GK a little bit to test his composure. Then see how he reacts to it, if he started to show an act of scoring, go back. If he show a sign of running go and get the ball from him. When it come to this point, all it matters is how you play mind games with him. Its not about skills anymore. Its all about the mind.
So try to test this out and please do tell me does it work for you or not. Remember in the end its all about be in control of the situation.
No matter what you do, be in control! ^^