Thow tons of pester balls into the rustling hedges on the Beach level and a Scyther will pop out. It helps if you stun Meowth on the tracks to slow down the Zero-One.
On the Beach Level, if you want to get a good shot of Pigeys, turn straight around at the beginning. Don't speed up and you can take pictures of three of them.
When you see the Pikachu at the Beach level, use apples to lead it toward the surf board. He will jump on it, making a great picture for lots of points.
Hit the Kangaskon in the Beach level and it will run at you. This makes a great picture.
At the end of the Volcano level, throw an apple at the Charmeleon by the lava pool. If you knock him into the lava he will evolve into a Charizard.
In the Volcano level, when you come to the egg that Moltres comes out of, dont throw the Pester Ball it it. Play your Poke Flute and then lots of Charmanders will come to you. Then, they will all line up and dance, but in order for the Charmanders to come to you, you must throw apples very close so the Charmanders will come to them. Then when the Charmanders come, that is when you play your Poke Flute, they will all line up and dance so you can get VERY good pictures.
At the end of the Volcano level where the Charmeleon is, turn right and you will see three pits. Throw pester balls and food into the pits and Growlithes will appear.
In the Volcano level, when you pass Moltres' egg and see Charmeleon, look right and through a Pester Balls in the 3 small volcanos. One will usually contain Arcanine. Aim well!
Throw Pester Balls in the pits across from Charmeleon in the Volcano level. Arcanine will appear sometimes. Get a photograph while it is shaking embers off its body for more points.
In the Valley Level, throw some pester balls into the whirlpool, and Dragonite will appear.
At the Valley, keep throwing pester balls at the shore near the first Mankey. A Magickarp will pop out and Mankey will throw it. Go to the three Gravelers and you will see the Magickarp. Throw a Pester Ball at it and it will flop to the waterfall, and a Gyarados will pop out.
In the Cave, there are two Grimers. Take lots of pictures of them. When the third one appears near the three Bulbasaurs, take a picture. Then throw lots of pester balls at him, and he will evolve into Muk.
In the Cave level, throw pester balls at the Bulbasaurs they will turn into Dittos.
In the Cave level, if you hit the Weepinbell into the pool of water it will evole into a Victreebell
In the Cave level throw a pester ball at a Zubat flying around carrying a Pikachu. Then Pikachu will fall from his grasp and Pikachu will deploy balloons to fall the ground safely. Take some well centered pictures to get a lot of points. Another one is after you do this, Hatch Articuno, and if you are lucky, he will fly away with Pikachu. This scene will give you even more points.
I got two e-mails with similar tips. Since I don't own the game, I can't verify which description is more accurate. So, here are both...
In the River level, if you lure the a Slowpoke over to the brown circle (try apples), it will turn around, put its tail in the water and evolve into a Slowbro.
In the River level, lure Slowpoke (try apples) to the sign that has Shellder on it. It will put its tail in the water and pick up a Shellder with it. Now it will evolve into a Slowbro.
In the River level, you will see a Staryu. Play your pokeflute and he will follow you to the whirlpool. Then he will jump in and evolve into a Starmie.
In the River level, you will see a whirlpool. Throw pester balls at it and Dragonite will come up.
On your way out from the River level, you'll see Pikachu standing on a log. Hit him with a pester ball, and he`ll run off. Take pictures for a "Speed Pkachu."
To get to the secret level (The Rainbow Cloud Stage) take pictures of the following landmarks on all of the 6 stages: Stage 1: The Kingler rock formation. It is on the left after you pass Pikachu's surfboard. Stage 2: The Pinsir shadow. After you pass the second Electabuzz, it will be on your right. Stage 3: The Koffing cloud. It appears on the left at the very beginning of the level. You should look for a volcano with purple smoke coming out of it. Toss a few pester balls into the volcano until a face appears. Stage 4: The Cubone rock formation. It is above the Vileplume (to see the Vileplume play the Pokeflute in front of a large purple bag you see near the beginning of the level). Stage 5: Mewtwo's energy form. It will appear on the left soon after you see the Weepinbell. Stage 6: The Dugtrio Rocks. They are right in front of you when you start the level.
In the Rainbow Cloud level, when Mew is out of his bubble, throw a pester ball at him. You will be able to take some good pictures.
On Level 5 there will be a Koffing chasing a Jigglypuff in three different spots. Throw Pokemon food or pester balls at the Koffing to make them stop. If you free all 3 Jigglypuffs, they will sing for you at the end of the level.
The second time you see Pikachu in the Tunnel level, lead him with apples to the Zapdos egg. Then play the Poke Flute. A lightning bolt will shoot out from the sky, and hit and hatch the egg. Take lots of pictures for points.
In the Tunnel level, photograph the Diglett that pops up next to the Pikachu. It will run away and Pikachu will run after it. Photograph the Diglett again. Repeat this process and Dugtrio will soon come up. If you miss a photo of Diglett once, you will have to start all over again.
At the tunnel level, when you see Pikachu for the first time, take a picture. He will run a few paces and stop, repeat the process, and he will leap on the passing electrode. He will ride on it until it explodes. Take lots of pictures for points.