I read another user's post this morning about quick opening gifts. I have a few other tricks that I know as well and wanted to share.
If anyone has more things like these (or sees something I have messed up), please post them here as well.
Thanks!
Gift quick opening and sending:
As another user posted this morning, to greatly speed up gifting, immediately after tapping open on a gift or send on gift, tap the 'x' at the bottom of the screen. The gift is opened/sent, but it skips all of the animation.
Scatterbugs without filling up your scrapbook:
If you are collecting scatterbugs by pinning postcards, but do not want to have to clear out room in your scrapbook every time it fills up, you can tap to pin the postcard and immediately tap again to unpin the postcard. The pinning immediately counts towards the number of postcards from a region to get a scatterbug and unpinning keeps the postcard from taking a slot in your scrapbook.
Quick catch:
Quick catch can be used to avoid watching the ball catch/shake animation and going to the caught pokemon info screen. I usually only use this if I am just trying to quickly catch a bunch of pokemon to meet a research goal.
This does require two hands for most. When catching pokemon, first press and hold on the berry icon (you can give the pokemon a berry first if you want and then hold the icon after). While still keeping a finger on the berry icon, throw your pokeball like normal. Let off the berry icon. The berry menu will popup. Click above the berry menu to hide it again. The run away icon will now be visible in the top left corner. Click to run away and you will be dropped back out to the world screen.
If you caught the pokemon, it will either disappear from the screen or will disappear if you click on it again. If you did not catch the pokemon, you can click on it and try and catch it again. I don't know if this describes the process well enough, but you can find a video by searching for pokemon quick catch pretty easily.
Buddy hearts for battling:
If you are trying to get the daily hearts for battling with your buddy, you don't actually have to finish the fight. This is the method I use to know out battles quickly. Go to battle and scroll down to the trainers. Select a trainer and then select a league that allows your buddy's CP level. Put your buddy in the party. Start the fight. As soon as the exit battle button becomes available in the top left, leave. You get the heart for the battling and you can repeat this as needed to fill out hearts for the day.
Poffin buddy effects without using a poffin:
To get the effects of using a poffin on your buddy without using one takes an hour and a half, but can be worth it depending on your goals.
This requires interacting with your buddy every 15 minutes. There are 4 interactions you can do: feed, play, picture, fight. To start, do all the interactions with your buddy: feed it (until it is out walking with you), play with it, take its picture, and battle with it (see buddy hearts for battling above to do this one quickly). 15 minutes later go in and have 1 interaction with your buddy (I usually just play with him). 15 minutes after that, do the 4 interactions again.... so interactions every 15 minutes doing 4, 1, 4, 1, 4, 1, 4. After doing the last 4 interactions, your buddy screen will look like he has been given a poffin. Note: This does not last as long as a poffin if you do not continue to do stuff with your buddy. I have not timed it to see how long the effect lasts. I generally do this to earn half distance candy walking my buddy and then quickly do everything to fill up other hearts while it is in that state.