There is so much great advice already, and @topblkmale is right, you need to spread your legs and hit those poppers and let a top fuck you often.
But if a real loose, puffy lipped hole is your goal, I'll share some advice a fellow bottom playmate once shared with me, and this is the plan I have in action currently. And he had the most beautiful, puffed out cunt lips I've ever seen, and he could regularly take a hard fucking from any top we encountered with no problem. So the proof is in the pudding, as they say.
Treat it like a workout. If say Monday is chest day, and Tuesday is leg day, etc., then Monday is stretch day, Tuesday is depth day, rest Wednesday, Thursday is grip day, rest Friday, Saturday is piston day, Sunday is control day. You should have something in your hole every day of the week, even if for just 10 minutes. So on rest days that means you're either taking dick, or using a small butt plug.
Here's how I do it:
1. Stretch Day. The goal is to teach your hole to open wider and wider. With all of these routines, start with something small and comfortable. The goal isn't pain, it's pleasure. So here I use the Topped Toys Gape Keepers. You could also use your standard issue butt plug trainer set, or the Square Peg Egg series. Whatever your budget allows. And don't go crazy, buy one and use it for a few months before buying your second. It's a marathon not a sprint.
So, for me, I get my 3 Gape Keepers lined up: the 100, 108, and 116. I get nice and relaxed and then slide down the 100. My goal is to just sit on it for 30-45 minutes. Mind you I started at 10 minutes. Set goals, work towards them slowly. Maybe a light bounce or grind, but your goal is to sit and get your hole used to the sensation of being open. Then I take it out and rest for about 5 minutes, on the the 108 for at least 15 minutes, and then on. I still struggle with the 116. Some days I can sit on it for about 5 minutes, some days I can't get it in at all. There was a time I couldn't leave the 100 in for more than 5 minutes. You'll get there.
2. Depth Day. The goal is teaching your deeper parts to get touched. And again, no thrusting or bouncing, put the whole thing up your chute and sit. Grind a little if you'd like, have fun. But you want your deep parts to get used to having something deep. That way when you get fucked,the top can slide in with little to no resistance because you're used to having something that deep. Get a collection of 3 dildos of varying lengths and sizes, and follow the same goal to sit on the deepest one for 20-45 minutes.
3. Grip Day. This is where you bust your ring so your top can slide right in. So named by Topped Toys Grip series. Likewise you could use their Mare Maker series. Get what you like. Same concept as Stretch Day, start with the smallest and work your way up. But instead of sitting on it, your going to do reps. EagerBttm on Just for Fans has some great workout vids I like to follow along. First do 10 reps just popping the widest part out and back in, then 20, then 40. Take a 2-5 minute rest. Then do 10 reps sit all the way down, pop it out as you stand all the way back up. The goal is to teach your hole to open, and then to pop. Then 20 reps, then start working your way up the next 2 sizes, same routine.
4. Piston Day. Get your favorite dildo, one you can take comfortably. Slide it in and out 10 times. Rest 30 seconds. Slide it all the way to the balls and all the way out 20 times. Rest 30 seconds. Slide it all the way in, and then all the way out. But this set when you take it out, concentrate on pushing your hole out/keep it open for 5 seconds between each rep. Do this 25 times. If at any point you can't keep your hole open, you start back at 1 until you are gaped between each rep for 25.
5. Control Day. Get a favorite, smallish comfortable plug. Maybe one of the small ones from your workout if you can hold it comfortably. If not get a smaller traditional one. Slide it in and walk around, do your chores, whatever around the house. Start with 10 minutes, work up to an hour.
Keep to this workout routine, and you will have a loose, easy hole for anyone to enjoy. Even take fists like a pro.
Sorry for the long post, but it's definitely worth the investment in resources, time, and energy.
Also, sign up for emails. The 3 sites I use most to get my toys (FortTroff, Mr. S, Topped Toys) all offer sales throughout the year. Figure out which toys you want to start, and then when the sales are announced, get what you want. For instance Topped does a "seconds" sale in early July on toys that have minor blemishes that work just fine, they just don't want to sell at full price. But these supplies are limited. So if you know what you want, you can grab it as soon as the sale goes live.
Anyway, hope that helps!