Here are some phrases that you can use in everyday speech to enhance your Welsh. I hope you find them useful.
In no particular order…
Heb os nac oni bai… Without a doubt Yn fy marn i … In my opinion Y dweud y gwir … To tell the truth Serch hynny … Despite that Ar y naill law … On the one hand Ar y llaw arall … On the other hand At hynny … In addition to that Ar yr un pryd… At the same time Cyn bo hir … Before long/soon Dim byd penodol … Nothing definite Dw i’n tybio … I suppose Gwell hwyr na hwyrach … Better late than never Mwy neu lai … More or less Man a man … Might as well Nawr ac yn y man … Now and again O dro i dro … From time to time Unwaith ac am byth … Once and for all Nac yma nac acw … Neither here nor there O ran … In terms of O ddydd y ddydd … From day to day Y tro diwetha … Last time Y tro nesa … Next time Yn ogystal â … As well as Yn fwy na dim … More than anything Yn enwedig … Especially Yn bendant dim … Definately not Yn amlach … More often Bron bob dydd … Nearly every day Cymaint â phosib … As much as possible Ar bob cyfrif … … Certainly/by all means Ar yn olwg … At a glance
And considering the lovely couple of days we’re having, don’t forget your elis haul. (suntan lotion)
I have heard the following also, which may or may not be correct! Would someone be able to correct any mistakes in usage, context, or spelling, please?
With all due respect.
 phob dydelus barch.
Gyda phob dydelus barch.
With regard to this/that.
 golwg ar hyn/hynny.
Gyda golwg ar hyn/hynny.
Anyway.
Beth bynnag.
In relation to/with…
Mewn perthynas i/â.
In connection with the…
Mewn cysylltiad â’r/gyda’r…
With regard to this/that.
Along with those, you may also hear o rhan hyn/hynny, ynghylch hyn/hynny, ynglŷn â hyn/hynny
In relation to/with… mewn perthynas â… (I’ve not come across using i instead of â here, but that’s not to say that no-one uses i), or you may hear mewn cysylltiad â…, or o ran…
In connection with the…
You can also use ynglŷn â’r…, ynghylch y/yr…, gyda golwg ar y/yr…,
As you can see, some of the phrases in Welsh match more than one of the phrases in English, but only because those English phrases have essentially the same meaning.
Beth bynnag (or, be’ bynnag’) is indeed the correct way to say “anyway”, however, you might also hear ta beth / ta be’ for this. And it’s also fairly common, in my experience, for people to say/write eniwe these days - which certainly makes some people shudder, but at least you know it’s out there!