For Rise of the Resistance, you need to try and get a boarding group. You can try at 7am for whichever ride is in the FIRST park you are entering that day. If you have a parkhopper, you can try at noon for the other ride, but only if you are not, at that time, holding a boarding group number.
At 6:55am and 11:55am, you open the app and click on "virtual queues" and then click on the rode you want. At xx:59, start pulling down your screen to refresh. Exactly at 7am and noon, you should be given a blue button that says "join now". Just click through on "join" on each page that opens. Don't stop to choose your party. It will automatically be checked off for you, just click through as fast as you can. If you succeed you will see your BG number and estimated wait time. The app will notify you when your BG is called and from that point, you have an hour to return to the ride.
Everything else is just good old standby. The wait times listed on the app may be accurate or not, but they will be in the ballpark.
There are also Single Rider lines for many attractions, so that is also an option.
Around 6pm, the parks clear out pretty massively, so take advantage of the later evening hours by staying in while everyone else leaves for dinner.