Thread I need tips on making vocals sit in the mix

I am very familiar with your problem. I've struggled many years with it, but have been steadily learning how to make those voc's blend in.
It's compression and EQ. Doubling helps but I now use doubling as more of an effect than anything else.

I start by using compression right at recording stage, then add more compression, as well as EQ during mixdown. Then there's compression and EQ that gets applied to the overall mix as well. That's three steps of compression; two to individual tracks and one to the overall mix. I try not to EQ vocals during recording, but if I have to I make sure I write down the exact settings and parameters that were used in case retakes are needed.
Generally, during recording I use a little more compression than during mixdown because I don't like real wide dynamics going to disc (or tape). It's not uncommon for me to set my threshold at -14dB or more and the ratio as high as infinity if the vocal part needs it. But as a rule of thumb I try to set my threshold and ratio settings so that I don't get more than -3dB of gain reduction (that's how much the signal gets squashed) when compressing individual tracks so that the texture or tembre of the voice isn't colored or changed, AND, to limit the amount of noise and pumping that is produced from compressing. Attack is usually around 0 and release around 100 ms. This applies to both recording and mixdown. The recording level is also very important, it should be between peak (0) and -4dB from peak. You can always turn down a loud vocal but when the fader is at its end and it still sounds weak your done. You can try to boost the volume using the compressor's output gain but this will undoubtedly add noise. Not good.
Overall compression during mixdown is a different story. Here you're looking to create a sound or feeling of unity where all the instruments can be heard but without dullness or annoying frequencies standing out. Gain reduction here can get as steep as -18dB depending on the printed dynamics of the other instruments, espcially drums, and, how "radio" you want it to sound. This is where a digital workstation that offers individualized EQ and dynamics for each track pays off.
This is also where EQ really has to be addressed as much if not more than compression. Finding the right frequencies to boost or cut for each individual instrument, and then on the overall mix is what really takes time and what really shapes the overall sound of the song. You don't want two instruments or tracks fighting for the same frequency. It's all trial and error here. It's an art of balancing levels and carving out the right EQ pattern for each sound source. There are "rules" that apply to EQ regarding certain instruments and problem frequencies but I've seen so many of these rules that i know they don't apply universally so you'll just have to experiment and listen to your mixes through different systems. When I mixdown I listen through a good pair of nearfield monitors, an old boombox from the 80's, a good pair of bass heavy headphones and a cheapy pair of headphones that will crackle at the very hint of overload.
But compression and EQ are how it's done.
One more important note: High end, expensive ($1000) eq's, compressors and preamps are very musical and quiet. So if you're not using these boxes remember to eliminate as much noise at every turn of the corner as possible because low end compressors, even high end (to a much lesser extent) will amplify it. Eq units are generally quiet but boosting the wrong frequency will add noise as well.

I ALWAYS go back to the arrangement when something sounds "cluttered" or "lost".

You can EQ and compress to your heart's delight, but if the song arrangement isn't making for enough space for the vocal, whether it be from other instrumentation clashing in the same frequency range, or whether it be music lines that are too busy at the wrong time.... you'll just be putting a band aid on it... and skewing your vocal track.

Always check your arrangement first. A great arrangement is easier to mix, assuming there's some degree of engineering chops involved.

A great song can make a listener's foot tap even through a clock radio. But a poor song will do nothing even if it's pumping through Hi-Fi gear.

Best of luck.