Just collected some things to think about from chat:

Think about why i let you use either green or purple beetles for sacrifices.
a purple beetle IS more rare than a green beetle, after all. but they're of the same genus. interdasting.

Each recipe has a certain percentage chance of success, which can be enhanced by using certain items in various tiers. Users will be informed whether their recipe is unsuccessful or simply invalid. Ingredients will be returned to inventory upon failing a valid recipe dev blog

SMASH FAILED = recipe is correct
NOTHING HAPPENED = recipe doesnt exist

Grigger Maxxing If you have a guaranteed recipe eg: smashing a Pincushion and a Bombardier beetle to create a Sabertooth Longhorn - you do not NEED to sacrifice a purple beetle or use an upgraded hammer - you can use a green beetle and a tin hammer - it will just take you a lot of griggers and a lot of tin hammers to get the recipe. I believe this is not the case if you're trying to upgrade flowers (by smashing two of like rarity together) or trying to upgrade like beetles.

i think maybe only the tiers matter
bwcause i used monarch and pond on the same kinda flower and got the same result
yahhh i think maybe only the different flowers in blue tuer matter

Hammer Upgrades Upgrading your hammer resets the break chance. So you can use it a few times at each tier and then upgrade before it breaks, to maximize your smashes per hammer. NOTE: If you push it too far you can lose your hammer at an intermediary tier, but the first smash is 0% break chance so you should always at least use it once before upgrading.

Daily Smash It has been observed that hammer break chance resets to 0% every day after Daily Cheese. However after using one time it goes back up to the previous break chance. Experts are uncertain of the exact mechanic, but it looks like we get one daily smash per hammer.

Inner Secrets of Rarity System Some cheesers (-Payback-) have reported that two Cattails do not assemble into Mithril pollen, despite Cattail being Mithril rarity. However it is confirmed that e.g. Morning Glory + Camellia produces Mithril pollen. And others have said that double Mithril flowers work well for pollen. So the system may be more complicated than previously thought…

Some upgrade pathways I saw posted in chat by charlotte and psi (I think):

pollen + ladybug = nectar, nectar + ladybug = upgraded beetle, upgraded beetle + junk = upgradded flower

as long as you have enough yellow flowers you can turn every 2 flowers into 1 blue flower

by doing 2 yellow flowers = pollen, + ladybug = nectar + ladybug = monarch + junk = blue flower

Goliath Beetle = (((Ladybug + ((Ladybug + Junk Cube)*1 Grigger + (Ladybug + Junk Cube)*1 Grigger)) + Ladybug) + (((Ladybug + ((Ladybug + Junk Cube)*1 Grigger + (Ladybug + Junk Cube)*1 Grigger)) + Ladybug) + ((((Ladybug + ((Ladybug + Junk Cube)*1 Grigger + (Ladybug + Junk Cube)*1 Grigger)) + Ladybug) + Junk Cube) + (((Ladybug + ((Ladybug + Junk Cube)*1 Grigger + (Ladybug + Junk Cube)*1 Grigger)) + Ladybug) + Junk Cube)*1 Grigger)))

Total for Goliath Beetle: 16 * Ladybug 10 * Junk Cube (or 20 Junk) 9 * Grigger

Goliath Beetle + 1 Junk Cube (or 2 Junk) + Purple Beetle = Adamantine Rarity Flower

Adamantine Rarity Flower * 2 = Adamantine Pollen

Adamantine Pollen = 32 Ladybug, 42 Junk, 1 Purple Beetle

Diamond Hammer = Adamantine Pollen + 3 Junk Cubes (or 6 Junk) + Adamantine Hammer