Can't Believe I waited This Long To Start The Scientist Career

First, when using the Sim ray, if the object is sitting on a table/counter, you'll only get another object that sits on a surface. But if you put it on the ground before transforming it, you can get anything. Also, it's the most profitable to buy a bunch of cheap objects, for instance the tissue box, to transform. You'll almost always get something more expensive.

Also, when your Sim does make it to Sixam, one of the objectives while there is to do a comedy routine. So you might want to make sure your Sim skills up enough to be able to do that. Sixam doesn't have anywhere for your Sim to fill their bladder need either. So you'll need to use the bb.enablefreebuild to put one down while there if your Sim wants to stay very long. Of course, that's if your Sim hasn't bought the reward trait so they never need to go anyway. :)

They supposedly fixed the plants issue in a patch, but if your lab garden is still borked, you can bring plants with you as suggested, but you could also click on the plant pot and buy seeds or just purchase them from your Sim's cell under the 'Purchase Gifts' option if you have Seasons.

If you've already invented the cloning machine, just put it down in the lab and clone any crystals/plants you need to make an invention if you find you only have one of several needed. I always tried to keep at least one of every kind; common, uncommon, rare in my Sims inventory. You could always just leave a duplicate cloning machine in the lab too. I always made copies of the cloning machine, freeze ray, satellite and worm hole generator so my Sim could have them at home and the lab. Plus, I liked to give other Sims in the family a copy of the freeze ray to play with too. lol

I don't know if it's necessary now since they got rid of suggested emotions for your Sims to be in while at work in a patch, but it couldn't hurt to be focused while there anyway. When it was necessary, I put an element near all the machines so my Sim was always focused while at work. I also had my painter Sim draw a couple mathematical diagrams and put one on the wall at work and home. You could also hang the paintings you get from using the microscope. Those all have focusing auras too.

Two of the best ways to get breakthroughs is by reading a book and taking a 'thoughtful' shower. Another really good way to have breakthroughs is while 'pondering moves' and playing chess. They can have them while gardening and fishing as well.

Lastly, when you get a work task where it wants you to interact with tourists, they can be found outside the lab compound at a little public area with two picnic tables and a grill. There's almost always Sims there making a ton of food too, so if your Sim is hungry and doesn't want to use the vending machine or microwave, just jog out there and snag a free meal. I usually just had my Sim take along a bunch of harvestables to eat, but in a pinch it was nice to know that was an option. :)

I have more tips, but I'll stop for now.

P.S. Oh! Almost forgot, waaaay up on the top floor is an observatory. Takes a long time to get there, lots of stairs, but if your Sim develops an office romance and needs a place to woohoo....lol Of course, you could always just use the freebuild cheat again and put a bed/closet in the basement too. I did put a bed down there myself, but just a single for my Sim to catch some extra Zzzzs if she had been out partying or skilling the previous night and didn't get much sleep before going to work. ;)

Gah! One more tip, a very important one. If you have other Sims at home and you notice their needs are tanking, you can click on and go back to your lot as that Sim, leaving your Sim at work. Don't worry, you'll be able to again click on your Sim to be at work with her afterward without any problem. At least that was my experience. Very handy to know when you follow your Sim to work and have others back home on the lot.